阅读说明：本技术 功率放大器功耗自适应装置及其方法 (Power amplifier power consumption self-adaption device and method thereof ) 是由 史翰缨 史建军 韩潇 于 2021-09-26 设计创作，主要内容包括：本发明提出了功率放大器功耗自适应装置及其方法,包括：传统功率放大器和自适应模块,所述自适应模块位于直流电源向功放单元供电的线路中,其中,所述自适应模块包括信号整理单元和可控开关电源,所述信号整理单元用于对来自所述传统功率放大器的工作信号进行信号相位和信号强度整理,生成适用于控制所述可控开关电源的控制信号,发送至所述可控开关电源；所述可控开关电源在所述控制信号的作用下,输出受控制的变化电压至功放单元进行供电,其中,所述可控开关电源输出电压强度与工作信号相关,输出至功放单元的供电电压随工作信号强度自动调节。(The invention provides a power amplifier power consumption self-adaptive device and a method thereof, wherein the power amplifier power consumption self-adaptive device comprises the following steps: the self-adaptive power amplifier comprises a traditional power amplifier and a self-adaptive module, wherein the self-adaptive module is positioned in a circuit for supplying power to a power amplification unit by a direct-current power supply, the self-adaptive module comprises a signal sorting unit and a controllable switching power supply, the signal sorting unit is used for sorting the signal phase and the signal intensity of a working signal from the traditional power amplifier, generating a control signal suitable for controlling the controllable switching power supply, and sending the control signal to the controllable switching power supply; the controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply under the action of the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity.)

1. An apparatus for power amplifier power consumption adaptation, comprising: a traditional power amplifier and an adaptive module, wherein the adaptive module is arranged in a line of a direct current power supply for supplying power to a power amplifier unit, wherein the adaptive module comprises a signal sorting unit and a controllable switch power supply,

the signal sorting unit is used for sorting the signal phase and the signal intensity of the working signal from the traditional power amplifier, generating a control signal suitable for controlling the controllable switching power supply and sending the control signal to the controllable switching power supply;

the controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply under the action of the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity.

2. The power amplifier power consumption adaptive apparatus according to claim 1, wherein the output voltage is high when the signal of the operation signal is strong and the output voltage is low when the signal is weak.

3. The power amplifier power consumption adaptive device according to claim 1, wherein an input end of the signal arrangement unit is connected to an output end of a digital-to-analog conversion unit of the conventional power amplifier, an input end of the digital-to-analog conversion unit is connected to an output end of a digital signal source of the conventional power amplifier, an output end of an analog signal source of the conventional power amplifier is connected to an input end of a pre-amplification unit, an output end of the pre-amplification unit is connected to an input end of the signal arrangement unit and an input end of a power amplification unit, and an input end of the power amplification unit is further connected to an output end of the digital-to-analog conversion unit, wherein the signal arrangement unit receives a working signal transmitted from the digital-to-analog conversion unit or the pre-amplification unit of the conventional power amplifier and adjusts the working signal.

4. The power amplifier power consumption adaptive apparatus of claim 3, wherein the signal grooming unit comprises: the operational amplifier is connected with the output end of the digital-to-analog conversion unit of the traditional power amplifier, and the operational amplifier is used for carrying out signal phase and signal intensity arrangement on the working signal from the traditional power amplifier.

5. The power amplifier power consumption adaptive apparatus of claim 1, wherein the signal grooming unit comprises: the input end of the built-in digital-to-analog conversion unit is connected with the output end of a digital signal source of the traditional power amplifier, the output end of the built-in digital-to-analog conversion unit is connected with the input end of the impedance matching unit, the output end of the digital signal source of the traditional power amplifier is further connected with the input end of the digital-to-analog conversion unit of the traditional power amplifier, and the output end of the digital-to-analog conversion unit of the traditional power amplifier is connected with the power amplifier unit.

6. The power amplifier power consumption adaptive device of claim 5, wherein the built-in digital-to-analog conversion unit receives a digital signal generated by a single chip, the single chip generates a digital signal meeting the requirements of signal phase and signal strength according to the operating state of the power amplification unit, the built-in digital-to-analog conversion unit converts the processed digital signal into an analog signal, and then the analog signal is transmitted to the impedance matching unit for processing.

7. The power amplifier power consumption adaptive apparatus according to claim 1, wherein the controllable switching power supply employs a buck switching power supply or a boost switching power supply.

8. The power amplifier power consumption adaptive apparatus of claim 1, wherein the signal arrangement unit performs signal phase arrangement on the operating signal comprises: performing phase inversion treatment; the signal arrangement unit is right the work signal carries out signal strength arrangement, includes: and amplifying or attenuating the signal intensity.

9. A power amplifier power consumption adaptive method is characterized by comprising the following steps:

step S1, embedding a self-adaptive module in a line of the power supply of the direct current power supply to the power amplification unit;

step S2, the adaptive module performs signal phase and signal strength sorting on the working signal from the conventional power amplifier, or converts the digital signal already containing phase and strength information into an analog signal, and generates a control signal suitable for controlling the controllable switching power supply;

and step S3, the controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply according to the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity.

10. The power amplifier power consumption adaptation method of claim 9, wherein the output voltage is high when the signal of the operating signal is strong and the output voltage is low when the signal is weak.

Technical Field

The invention relates to the technical field of power amplifiers, in particular to a power amplifier power consumption self-adaption device and a power amplifier power consumption self-adaption method.

Background

In the medical field, the traditional linear power amplifier (without involving a digital class-D power amplifier) has the advantages of mature and reliable technology, no high-frequency power radiation source and the like, and is widely used in active medical instruments. In the prior art, a conventional linear power amplifier is generally powered by a constant direct current power supply. The output signal intensity range of the power amplifier is very wide, the output intensity is adjusted at any time according to the requirement in work, in order to guarantee the power supply requirement when the maximum intensity, the power supply voltage is designed to be supplied with power according to the highest voltage, and the equipment is rarely output with the maximum intensity in actual work, so the power supply voltage is far higher than the actual requirement for most of time, the power amplification unit generates useless power loss due to the overhigh power supply voltage, the power amplification unit generates serious heat, and a plurality of equipment can work only by means of a complex heat dissipation system. Fig. 1 is a block diagram of a conventional power amplifier.

The typical features of the prior art described above are: the equipment has higher heat generation, a more complex heat dissipation system, poorer energy consumption of the equipment, lower energy consumption efficiency, larger volume, weight and noise (when air cooling is adopted) of the equipment and higher cost.

Disclosure of Invention

The object of the present invention is to solve at least one of the technical drawbacks mentioned.

Therefore, the invention aims to provide a power amplifier power consumption adaptive device and a method thereof

In order to achieve the above object, an embodiment of an aspect of the present invention provides a power amplifier power consumption adaptive apparatus, including: a traditional power amplifier and an adaptive module, wherein the adaptive module is arranged in a line of a direct current power supply for supplying power to a power amplifier unit, wherein the adaptive module comprises a signal sorting unit and a controllable switch power supply,

the signal sorting unit is used for sorting the signal phase and the signal intensity of the working signal from the traditional power amplifier, generating a control signal suitable for controlling the controllable switching power supply and sending the control signal to the controllable switching power supply;

the controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply under the action of the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity.

Further, when the signal of the working signal is strong, the output voltage is high, and when the signal is weak, the output voltage is low.

Further, the input end of the signal sorting unit is connected with the output end of the digital-to-analog conversion unit of the conventional power amplifier, the input end of the digital-to-analog conversion unit is connected with the output end of the digital signal source of the conventional power amplifier, the output end of the analog signal source of the conventional power amplifier is connected with the input end of the preamplification unit, the output end of the preamplification unit is connected with the input end of the signal sorting unit and the input end of the power amplification unit, the input end of the power amplification unit is further connected with the output end of the digital-to-analog conversion unit, and the signal sorting unit receives a working signal transmitted by the digital-to-analog conversion unit or the preamplification unit of the conventional power amplifier and adjusts the working signal.

Further, the signal arrangement unit includes: the operational amplifier is connected with the output end of the digital-to-analog conversion unit of the traditional power amplifier, and the operational amplifier is used for carrying out signal phase and signal intensity arrangement on the working signal from the traditional power amplifier.

Further, the signal arrangement unit includes: the input end of the built-in digital-to-analog conversion unit is connected with the digital signal output end of the traditional power amplifier, the output end of the built-in digital-to-analog conversion unit is connected with the input end of the impedance matching unit, the output end of a digital signal source of the traditional power amplifier is further connected with the input end of the digital-to-analog conversion unit of the traditional power amplifier, and the output end of the digital-to-analog conversion unit of the traditional power amplifier is connected with the power amplifier unit.

Further, the built-in digital-to-analog conversion unit receives a digital signal generated by a single chip microcomputer, the single chip microcomputer generates a digital signal meeting the requirements of signal phase and signal intensity according to the working state of the power amplification unit, and the built-in digital-to-analog conversion unit converts the processed digital signal into an analog signal and transmits the analog signal to the impedance matching unit for processing.

Further, the controllable switch power supply adopts a voltage reduction switch power supply or a voltage boosting switch power supply.

Further, the signal phase arrangement of the working signal by the signal arrangement unit includes: performing phase inversion treatment; the signal arrangement unit is right the work signal carries out signal strength arrangement, includes: and amplifying or attenuating the signal intensity.

An embodiment of another aspect of the present invention provides a power amplifier power consumption adaptive method, including the following steps:

step S1, embedding a self-adaptive module in a line of the power supply of the direct current power supply to the power amplification unit;

step S2, the adaptive module performs signal phase and signal strength sorting on the working signal from the conventional power amplifier, or converts the digital signal already containing phase and strength information into an analog signal, and generates a control signal suitable for controlling the controllable switching power supply;

and step S3, the controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply according to the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity.

Further, when the signal of the working signal is strong, the output voltage is high, and when the signal is weak, the output voltage is low.

According to the power amplifier power consumption self-adaption device and the power amplifier power consumption self-adaption method, the problems of heating, poor energy consumption ratio, large volume and weight and the like of a traditional power amplifier in the prior art are solved. The power supply voltage is automatically adjusted along with the signal intensity, the power supply voltage is high when the signal is strong, the power supply voltage is low when the signal is weak, useless power loss is reduced, power consumption self-adaption is realized on the premise of ensuring that the amplified signal is not distorted, the power consumption of a traditional power amplifier is reduced, heating is avoided, and the working efficiency is improved.

The invention adds a self-adaptive module in the power supply loop of the traditional power amplifier, changes the stable power supply of the power amplifier unit into the power supply which is automatically adjusted along with the working signal intensity and has amplitude change, reduces the useless power loss of the power amplifier unit and realizes the power consumption self-adaptation. The device and the method can obviously reduce the self power consumption of the power amplifier under the condition of outputting the same power signal, and the power consumption of the whole machine is optimized because the controllable switch power supply in the self-adaptive module is a digital circuit, the working efficiency can reach more than 80 percent, and the useless power consumption of the power amplification unit can reach the lowest under the working conditions of various signal intensities. The device and the method of the invention solve the problem of serious heating of the traditional power amplifier circuit, can greatly reduce the power performance requirement of the power amplifier unit, simplify or even cancel the heat dissipation configuration (comprising a radiator, an air cooling device, a water cooling device and the like) of the power amplifier unit, can reduce the volume and the weight of equipment, can prolong the battery working time of portable equipment, can reduce the manufacturing cost of the equipment, and can improve the energy consumption ratio index of the equipment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a structural view of a conventional power amplifier;

fig. 2 is a block diagram of a power amplifier power consumption adaptive apparatus according to a first embodiment of the present invention;

fig. 3 is a block diagram of a power amplifier power consumption adaptive apparatus according to a second embodiment of the present invention;

fig. 4 is a flowchart illustrating a power consumption adaptive method of a conventional power amplifier according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The invention provides a power amplifier power consumption self-adaption device and a power amplifier power consumption self-adaption method, which are suitable for the electronic technical field of active medical equipment, traditional power amplifiers and the like and can reduce the power consumption of equipment.

As shown in fig. 2, the power amplifier power consumption adaptive apparatus according to the embodiment of the present invention includes: the self-adaptive power amplifier comprises a traditional power amplifier and a self-adaptive module, wherein the self-adaptive module is positioned in a circuit for supplying power to a power amplification unit by a direct-current power supply. The self-adaptive module comprises a signal sorting unit and a controllable switch power supply.

The signal arrangement unit is used for carrying out signal phase and signal intensity arrangement on working signals from the traditional power amplifier, generating control signals suitable for controlling the controllable switching power supply and sending the control signals to the controllable switching power supply.

The controllable switch power supply outputs controlled variable voltage to the power amplification unit for power supply under the action of the control signal, wherein the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity. In the embodiment of the invention, when the signal of the working signal is strong, the output voltage is high, and when the signal is weak, the output voltage is low.

In the embodiment of the invention, the controllable switching power supply can be a step-down switching power supply or a step-up switching power supply according to the requirements of the actual circuit structure. The working efficiency of the switching power supply is higher and generally can reach more than 80%, and the working efficiency of the whole circuit can be ensured.

It should be noted that the power supplied by the power amplifier unit is not a stable dc power supply, but a dc power supply whose voltage varies with the signal strength in real time is provided by the controllable switching power supply. In the adaptive module, the input voltage of the controllable switching power supply is constant direct current, and the output voltage of the controllable switching power supply is not constant. The output voltage of the controllable switching power supply is controlled by a signal sent by the signal arrangement, the output voltage is high when the signal is strong, and the output voltage is low when the signal is weak; namely, the power supply voltage of the power amplification unit of the equipment is automatically adjusted along with the signal intensity, and the power supply voltage automatically adapts to the change of the signal intensity, so that the idle power loss of the power amplification unit is reduced to the minimum, and the power consumption self-adaptation is realized.

The controllable switching power supply has good regulation characteristics: firstly, the voltage which can be changed within a certain range can be output according to the control of a control signal; secondly, the regulation of the output voltage has better linearity; thirdly, the control signal can be quickly and timely responded, so that the change of the output voltage can be real-timely followed with the intensity change of the working signal, and the power consumption self-adaption is achieved.

The power supply voltage of the power amplification unit is provided by the self-adaptive module, the power supply voltage is non-constant, and the power supply voltage automatically changes along with the intensity of the working signal. The power supply voltage is high when the signal is strong, the power supply voltage is low when the signal is weak, and the power supply voltage is always kept at the lowest value when the power amplification unit can amplify signals with different strengths without distortion, so that power consumption self-adaption is realized, useless power loss caused by overhigh power supply voltage is avoided, and the working efficiency of the power amplification unit is improved.

In the invention, the signal arrangement unit can receive the analog signal sent by preamplification and can also receive the analog signal obtained by digital-to-analog conversion of the digital signal. The signal arrangement unit processes the received signal and outputs the processed signal, and the output signal of the signal arrangement unit is used as a control signal of the controllable switching power supply.

The input end of the signal sorting unit is connected with the output end of a digital-to-analog conversion unit of a traditional power amplifier, the input end of the digital-to-analog conversion unit is connected with the output end of a digital signal source of the traditional power amplifier, the output end of an analog signal source of the traditional power amplifier is connected with the input end of a pre-amplification unit, the output end of the pre-amplification unit is connected with the input end of the signal sorting unit and the input end of a power amplification unit, the input end of the power amplification unit is further connected with the output end of the digital-to-analog conversion unit, and the signal sorting unit receives working signals transmitted by the digital-to-analog conversion unit or the pre-amplification unit of the traditional power amplifier and adjusts the working signals.

The signal arrangement unit includes: and the operational amplifier is connected with the output end of the digital-to-analog conversion unit of the traditional power amplifier, and the operational amplifier is used for carrying out signal phase and signal intensity arrangement on the working signal from the traditional power amplifier. Specifically, the signal arrangement unit processes the signal according to the characteristics of the actually used controllable switching power supply: firstly, signal phase processing is carried out, and phase inversion is carried out on signals when necessary; second, signal intensity processing, which amplifies or attenuates the signal if necessary.

Referring to fig. 2, the power amplifier power consumption adaptive apparatus includes a conventional power amplifier a and an adaptive module B. The traditional power amplifier A comprises an analog signal source A-1, a pre-amplification unit A-2, a digital signal source A-3, a digital-to-analog conversion unit A-4, a direct-current power supply A-5 and a power amplification unit A-6. The self-adapting module B comprises a signal arranging unit B-1 and a controllable switch power supply B-2. The pre-amplification unit A-2 and the digital-to-analog conversion unit A-4 are connected with the signal sorting unit B-1, the signal sorting unit B-1 is connected with the control end of the controllable switch power supply B-2, the output end of the direct current power supply A-5 is connected with the input end of the controllable switch power supply B-2, and the output end of the controllable switch power supply B-2 is connected with the power supply end of the power amplification unit A-6. The method comprises the following steps: the analog signal is preamplified or the digital signal is sent to the signal arrangement unit B-1 after digital-to-analog conversion, the signal is sent to the controllable switch power supply B-2 after phase and intensity arrangement, the output voltage of the controllable switch power supply B-2 is controlled by the signal and sent to the power amplification unit A-6, the power supply voltage of the power amplification unit A-6 is automatically adjusted along with the signal intensity, the power supply voltage is high when the signal is strong, the power supply voltage is low when the signal is weak, useless power loss is reduced, on the premise that the amplified signal is not distorted, power consumption self-adaption is realized, the power consumption of the power amplifier is reduced, heating is avoided, and the working efficiency is improved.

In addition, as shown in fig. 3, the present invention also provides a new power consumption adaptive circuit combination mode, the basic principle is not changed, only the operational amplifier in the signal arrangement unit is changed into the built-in digital-to-analog conversion unit B-13, the single chip microcomputer alone provides a path of data to control the B-13, the phase and numerical value problems originally processed by the operational amplifier are all processed by the single chip microcomputer in a digital manner, and the built-in digital-to-analog conversion unit B-13 converts the digital signals into the required analog signals.

The signal arrangement unit includes: the input end of the built-in digital-to-analog conversion unit is connected with the output end of a digital signal source (provided by a single chip microcomputer) of the traditional power amplifier, the output end of the built-in digital-to-analog conversion unit is connected with the input end of the impedance matching unit, the output end of the digital signal source of the traditional power amplifier is further connected with the input end of the digital-to-analog conversion unit of the traditional power amplifier, and the output end of the digital-to-analog conversion unit of the traditional power amplifier is connected with the power amplifier unit.

The built-in digital-to-analog conversion unit receives a digital signal of the single chip microcomputer, the single chip microcomputer generates a digital signal meeting the requirements of signal phase and signal intensity according to the working state of the power amplification unit, the built-in digital-to-analog conversion unit converts the processed digital signal into an analog signal, and the analog signal is transmitted to the impedance matching unit for processing.

Specifically, the internal digital-to-analog conversion unit of the signal processing unit converts the digital signal into an analog signal, and the digital signal received by the internal digital-to-analog conversion unit is subjected to necessary signal phase processing and signal intensity processing according to the characteristics of the actually used controllable switching power supply, and the digital processing is completed by a preceding-stage digital signal source (single chip microcomputer). Then the signal impedance is matched and connected with the controllable switch power supply through proper impedance conversion to obtain proper control range of the controllable switch power supply.

As shown in fig. 4, an embodiment of the present invention further provides a power amplifier power consumption adaptive method, including the following steps:

step S1, embedding self-adapting module in the line of DC power supply to power amplifier unit.

Specifically, compared with the traditional power amplifier, the self-adaptive module is embedded in a line of a direct-current power supply for supplying power to the power amplification unit.

In step S2, the adaptive module performs signal phase and signal strength matching on the working signal from the conventional power amplifier to generate a control signal suitable for controlling the controllable switching power supply.

In the signal arrangement part of the adaptive module, the working signal is subjected to phase and intensity arrangement, or a digital signal which already contains phase and intensity information is converted into an analog signal. A control signal is obtained which is suitable for controlling the controllable switching power supply.

And step S3, the controllable switch power supply outputs the controlled variable voltage to the power amplification unit for power supply according to the control signal, wherein, the output voltage intensity of the controllable switch power supply is related to the working signal, and the power supply voltage output to the power amplification unit is automatically adjusted along with the working signal intensity. In an embodiment of the invention, the control signal characteristic is closely related to an operating signal under which the controllable switching power supply is operated. The output voltage intensity is closely related to the working signal, the output voltage is high when the signal is strong, and the output voltage is low when the signal is weak. The direct current power supply becomes non-constant voltage after passing through the self-adaptive module and supplies power to the power amplification unit.

The controllable switch power supply outputs non-constant variable voltage to supply power to the power amplification unit, the power supply voltage of the power amplification unit is not constant, the power supply voltage automatically changes along with the intensity of the working signal, and useless loss generated by overhigh power supply voltage in the power amplification unit is avoided, so that power consumption self-adaption is realized.

According to the power amplifier power consumption self-adaption device and the power amplifier power consumption self-adaption method, the problems of heating, poor energy consumption ratio, large volume and weight and the like of a traditional power amplifier in the prior art are solved. The power supply voltage is automatically adjusted along with the signal intensity, the power supply voltage is high when the signal is strong, the power supply voltage is low when the signal is weak, useless power loss is reduced, power consumption self-adaption is realized on the premise of ensuring that the amplified signal is not distorted, the power consumption of a traditional power amplifier is reduced, heating is avoided, and the working efficiency is improved.

The invention adds a self-adaptive module in the power supply loop of the traditional power amplifier, changes the stable power supply of the power amplifier unit into the power supply which is automatically adjusted along with the working signal intensity and has amplitude change, reduces the useless power loss of the power amplifier unit and realizes the power consumption self-adaptation. The device and the method can obviously reduce the self power consumption of the traditional power amplifier under the condition of outputting the same power signal, and the power consumption of the whole power amplifier is optimized because the controllable switch power supply in the self-adaptive module is a digital circuit, the working efficiency can reach more than 80 percent, and the useless power consumption of a power amplification unit can reach the lowest under the working conditions of various signal strengths. The device and the method of the invention solve the problem of serious heating of the traditional power amplifier circuit, can greatly reduce the power performance requirement of the power amplifier unit, simplify or even cancel the heat dissipation configuration (comprising a radiator, an air cooling device, a water cooling device and the like) of the power amplifier unit, can reduce the volume and the weight of equipment, can prolong the battery working time of portable equipment, can reduce the manufacturing cost of the equipment, and can improve the energy consumption ratio index of the equipment.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.