阅读说明：本技术 一种可调程控陷波滤波器 (Adjustable program-controlled notch filter ) 是由 赵智兵 徐保根 彭志华 颜妍 童慧超 熊萨莉 于 2020-12-03 设计创作，主要内容包括：本发明公开了一种可调程控陷波滤波器,包括波段切换开关一、波段切换开关二,波段切换开关一分别与若干个陷波器的输入端相连,波段切换开关二与若干个陷波器的输出端相连；陷波器的两端均与隔直电容串联,波段切换开关一与波段切换开关二的波段切换电平为SELi,波段切换电平SELi与控制信号驱动电路相连,控制信号驱动电路内设置有三极管,其中,陷波器为可调程控陷波器。本发明提供一种可调程控陷波滤波器,能够实现跟踪干扰信号频率并进行抑制,并且能够吸收阻带反射信号的能量,提高系统电磁兼容效能；同时,还具有调谐范围宽、陷波深度深、频率选择性好等优点,并且由于采用集总元件,制作简单易加工,可应用于无线通信、雷达及电子对抗领域。(The invention discloses an adjustable program-controlled notch filter, which comprises a first wave band switch and a second wave band switch, wherein the first wave band switch is respectively connected with the input ends of a plurality of wave traps, and the second wave band switch is connected with the output ends of the plurality of wave traps; two ends of the wave trap are connected with the blocking capacitor in series, the waveband switching level of the first waveband switching switch and the waveband switching level of the second waveband switching switch are SELi, the waveband switching level SELi is connected with the control signal driving circuit, a triode is arranged in the control signal driving circuit, and the wave trap is an adjustable program-controlled wave trap. The invention provides an adjustable program-controlled notch filter, which can track the frequency of an interference signal and inhibit the frequency, absorb the energy of a stop band reflected signal and improve the electromagnetic compatibility of a system; meanwhile, the tunable filter has the advantages of wide tuning range, deep trapped wave depth, good frequency selectivity and the like, and is easy to manufacture and process due to the adoption of the lumped element, so that the tunable filter can be applied to the fields of wireless communication, radars and electronic countermeasure.)

1. A tunable program-controlled notch filter is characterized by comprising a first wave band switch and a second wave band switch, wherein the first wave band switch is respectively connected with the input ends of a plurality of wave traps, and the second wave band switch is connected with the output ends of the plurality of wave traps; the both ends of trapper all establish ties with blocking capacitance, the wave band shift switch one is SELi with the wave band shift switch two the wave band switching level, wave band switching level SELi links to each other with control signal drive circuit, be provided with the triode in the control signal drive circuit, wherein, the trapper is adjustable programme-controlled trapper.

2. The tunable programmable notch filter of claim 1, wherein the notch filter comprises a plurality of notch sub-bands for meeting the requirement of full band coverage, the upper branch of the notch sub-bands is a high pass filter, and the lower branch of the notch sub-bands is a dual resonant tank coupled by a capacitor.

3. The tuneable programmable notch filter of claim 2, wherein the band switching level SELi is adapted to be compatible with TTL levels and CMOS levels, and is connected with an external switch control level YNi, where i =1, 2 or 3.

4. The tunable programmable notch filter of claim 1, wherein a switch control circuit is disposed in each of the first band switch and the second band switch, and a PIN is disposed in the switch control circuit, and the PIN is MA4P 4001F.

5. The tunable programmable notch filter of claim 1, further comprising a resonant tank, wherein the resonant tank is provided with a resonant capacitor, and the resonant capacitor is a varactor diode.

6. The tunable programmable notch filter of claim 1, wherein the first band switch is an rf input interface RFin and the second band switch is an rf output interface RFout.

7. The tunable programmable notch filter of claim 1, wherein the transistor is of the type MMBT 2222.

Technical Field

The invention relates to the technical field of radio frequency filters, in particular to an adjustable program-controlled notch filter.

Background

With the rapid development of wireless communication technology, the problem of spectrum resource congestion is particularly prominent, and in order to improve the utilization rate of spectrum resources, the technologies such as frequency hopping and dynamic frequency allocation are widely applied. On the other hand, along with the continuous improvement of the digitalization, informatization and automation degree of military equipment, the integration degree of a military system platform is increased in a geometric index manner and is limited by space, the problem of electromagnetic compatibility among equipment such as radars, radio stations and receivers among systems is particularly important, and the use efficiency of the equipment is severely limited.

Specifically, for the short-wave frequency spectrum, the short-wave communication signal is mainly transmitted by reflection of an ionosphere, and is greatly influenced by ionosphere activity and multipath effect, and various industrial interferences are added, so that the electromagnetic environment of the short-wave frequency band is extremely complex, and large signals are quite large. To accommodate real-time detection of signals such as frequency hopping, the short-wave receiver front-end circuitry is typically wide-open, so that strong interfering signals fall within the receiver band. Strong interference signals in the receiver band can cause the amplifier in the front-end circuit to enter a nonlinear state, deteriorate the effective receiving performance of the useful signal, and also cause intermodulation products to be generated in the receiver, thereby causing false early warning.

In order to suppress the in-band strong interference signal, a pre-preselection band-pass filter can be considered to carry out 'slotting' treatment, the slotting place is a wave trap which has great attenuation effect on the interference signal falling into the slot, and the processing mode has the defects that the frequency point of the suppressed strong interference signal is relatively fixed and can not be flexibly changed, namely, the frequency of the interference signal can not be well tracked and suppressed, so that the requirement is provided for the adjustable parameter program control wave trap filter.

Conventionally, the design of a programmable notch filter with adjustable parameters is based on a reflection principle, which means that signal energy suppressed by a stop band is reflected back through the filter, and the notch depth of the notch filter is greatly influenced by the Q value of a component, so that a good suppression effect cannot be achieved.

Disclosure of Invention

Aiming at the problems in the related art, the invention provides an adjustable program-controlled notch filter, which solves the problems that the frequency point of a strong interference signal suppressed by the existing program-controlled notch filter is relatively fixed and can not be flexibly changed, namely the frequency of the interference signal can not be well tracked and suppressed.

In order to achieve the technical purpose, the technical scheme of the invention is as follows:

designing an adjustable program-controlled notch filter, which comprises a first wave band switch and a second wave band switch, wherein the first wave band switch is respectively connected with the input ends of a plurality of wave traps, and the second wave band switch is connected with the output ends of the plurality of wave traps; the both ends of trapper all establish ties with blocking capacitance, the wave band shift switch one is SELi with the wave band shift switch two the wave band switching level, wave band switching level SELi links to each other with control signal drive circuit, be provided with the triode in the control signal drive circuit, wherein, the trapper is adjustable programme-controlled trapper.

Further, the wave trap comprises a plurality of wave trap sub-bands for meeting the requirement of full-band coverage, the upper branch of the wave trap sub-bands is a high-pass filter, and the lower branch of the wave trap sub-bands is a double resonance loop coupled through capacitance.

Further, the band switching level SELi is used to be compatible with a TTL level and a CMOS level, and an external switch control level YNi is connected, where i =1, 2, or 3.

Further, switch control circuits are arranged in the first wave band switch and the second wave band switch, PIN tubes are arranged in the switch control circuits, and the types of the PIN tubes are MA4P 4001F.

Further, the adjustable program-controlled notch filter further comprises a resonant circuit, wherein a resonant capacitor is arranged in the resonant circuit, and the resonant capacitor adopts a variable capacitance diode.

Further, the first band switch is a radio frequency input interface RFin, and the second band switch is a radio frequency output interface RFout.

Further, the type of the triode is MMBT 2222.

The invention has the beneficial effects that: aiming at the characteristic that the electromagnetic environment of a short wave frequency band is extremely complex, the adjustable program-controlled notch filter can track the frequency of an interference signal and inhibit the frequency, can absorb the energy of a stop band reflected signal, can obviously reduce intermodulation components generated in a receiver band by inhibiting or attenuating a strong interference signal, can also effectively solve the problem of co-location interference among equipment of a military system platform, and improves the electromagnetic compatibility efficiency of the system; meanwhile, the tunable filter has the advantages of wide tuning range, deep trapped wave depth, good frequency selectivity and the like, and is easy to manufacture and process due to the adoption of the lumped element, so that the tunable filter can be applied to the fields of wireless communication, radars and electronic countermeasure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a block diagram of an architecture of a tunable programmable notch filter according to an embodiment of the present invention;

FIG. 2 is a circuit schematic of a tunable programmable notch filter according to an embodiment of the present invention;

FIG. 3 is a circuit schematic of band switching levels in a tunable programmable notch filter according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a sub-band of a notch filter in a tunable programmable notch filter according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

As shown in fig. 1, the tunable programmable notch filter according to the embodiment of the present invention includes a first band switch and a second band switch, where the first band switch is respectively connected to input ends of a plurality of wave traps, and the second band switch is connected to output ends of the plurality of wave traps; the both ends of trapper all establish ties with blocking capacitance, the wave band shift switch one is SELi with the wave band shift switch two the wave band switching level, wave band switching level SELi links to each other with control signal drive circuit, be provided with the triode in the control signal drive circuit, wherein, the trapper is adjustable programme-controlled trapper.

As shown in fig. 1 and 4, in this embodiment, the wave trap further includes a plurality of wave trap sub-bands for meeting the requirement of full-band coverage, an upper branch of the wave trap sub-bands is a high-pass filter, and a lower branch of the wave trap sub-bands is a dual resonant loop coupled by a capacitor.

As shown in fig. 1-4, in the present embodiment, the band switching level SELi is used to be compatible with TTL level and CMOS level, and an external switch control level YNi is connected, where i =1, 2, or 3.

As shown in fig. 1-2, in the present embodiment, a switch control circuit is disposed in each of the first band switch and the second band switch, a PIN is disposed in the switch control circuit, and the PIN is MA4P 4001F.

As shown in fig. 1 to 4, in this embodiment, the tunable programmable notch filter further includes a resonant tank, and a resonant capacitor is disposed in the resonant tank, and the resonant capacitor is a varactor.

As shown in fig. 1-2, in the present embodiment, the first band switch is a radio frequency input interface RFin, and the second band switch is a radio frequency output interface RFout.

As shown in fig. 1-4, in the present embodiment, the type of the triode is MMBT 2222.

In order to facilitate further understanding of the above technical solutions, the working principle thereof will now be explained:

as shown in fig. 1, the tunable programmable notch filter mainly includes two stages of switches and three sub-band tunable programmable traps. As shown in fig. 2, the band switch is implemented by using a PIN, and a voltage of +3.3V is applied to an anode of the PIN, and when a level of a band switching level SELi (i =1, 2, 3) is 0V, the PIN of the branch in which the PIN is located is turned on, the branch is turned on, and when the level of the band switching level SELi is +12V, the PIN of the branch in which the PIN is located is turned off, and the branch is turned off. As in fig. 3, the external switch control level YNi (i =1, 2, 3) is compatible with TTL level and MOS level, and when YNi is low, the level of SELi is pulled high, and when YNi is high, the level of SELi is pulled low. As shown in fig. 4, a circuit diagram for implementing a sub-band of a trap is shown, an incident wave is divided into two parts at an input end, and is transmitted through two branches, an upper branch is a high-pass filter, a lower branch is a dual resonant circuit coupled by a capacitor, wherein a resonant capacitor is implemented by using a varactor, VCT is a tuning voltage, two signals are converged at an output end, and the two signals are combined through 'equal amplitude and opposite phase' at a resonant frequency, so that an absorption trap is achieved.

When the tunable programmable notch filter is used specifically, the frequency range of the tunable programmable notch filter covers 1.5 MHz-30 MHz, and the tunable range of the varactor device is considered, and the tunable programmable notch filter is realized by dividing the tunable programmable notch filter into three parts, namely 1.5 MHz-4 MHz, 4 MHz-10 MHz and 10 MHz-30 MHz. The three parts of the change-over switches are realized by adopting high-performance PIN tubes, good switching and isolating effects are achieved by utilizing the characteristics of forward conduction and reverse cut-off of the three parts of the change-over switches, and the type of the PIN tubes is MA4P 4001F. The trap characteristic of each part is achieved in an absorption mode, incident waves are transmitted through two branches respectively, and two paths of signals are offset at a junction point due to equal-amplitude reverse phase at a resonant frequency, so that a trap effect is generated. The switch switching signal driving circuit is realized by adopting a triode, and the model of the triode is selected to be MMBT 2222.

In the description of the present invention, it is to be understood that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings and are only for convenience in describing the present invention and simplifying the description, but are not intended to indicate or imply that the indicated devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the present invention.

In the present invention, unless otherwise explicitly specified or limited, for example, it may be fixedly attached, detachably attached, or integrated; the two components can be connected electrically, directly or indirectly through an intermediate medium, and can be connected internally or in an interaction relationship, and unless otherwise specifically limited, the specific meaning of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

It is noted that, in this document, relational terms such as "component" a "and" component "and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.