阅读说明：本技术 具有陷波滤波器的滤波器电路 (Filter circuit with notch filter ) 是由 R·海贾纳 于 2019-01-28 设计创作，主要内容包括：一种滤波器电路,在信号线中包括：带滤波器(BF),允许让有用频带通过；以及陷波滤波器(NF),串联地电路连接到带滤波器以滤除阻带频率。陷波滤波器包括多个并联分流元件(SE1…SE6)的串联电路,其中每个分流元件的频率相对于其他分流元件的频率发生偏移,分流元件的频率被分布(f1…F6)在陷波带上。所有分流元件可以被实现为包括具有不同间距的区域的SAW单端口谐振器(TR<Sub>NF</Sub>)。(A filter circuit comprising, in a signal line: a Band Filter (BF) allowing the useful frequency band to pass; and a Notch Filter (NF) electrically connected in series to the band filter to filter out the stop band frequency. The notch filter comprises a series circuit of a plurality of shunt elements (SE1 … SE6) connected in parallel, wherein the frequency of each shunt element is shifted with respect to the frequency of the other shunt elements, the frequency of the shunt elements being distributed (F1 … F6) over a notch band. All shunt elements can be implementedNow a SAW single-port resonator (TR) comprising regions with different pitches NF )。)

1. A filter circuit comprising in a Signal Line (SL):

-a Band Filter (BF) allowing the useful frequency band to pass; and

-a Notch Filter (NF) electrically connected in series to the band filter for filtering out stop band frequencies;

wherein

-the notch filter comprises a series circuit of a number n of Shunt Elements (SE) in parallel,

-the frequency of each shunt element (SE1, SE 2.. SEn) is shifted with respect to the frequencies of the other shunt elements, all shunt elements being distributed over the notch band,

-said Notch Filter (NF) providing said Notch Band (NB).

2. The filter circuit according to the preceding claim,

wherein the parallel Shunt Element (SE) is selected from a resonator (R) electrically connected in parallel to the Signal Line (SL),

wherein each shunt element has a smaller admittance of about 1/n times the admittance of a normal Notch Filter (NF), where n is said number of shunt elements.

3. The filter circuit according to the preceding claim,

wherein the parallel Shunt Element (SE) is selected from a resonator (R) operating with acoustic waves.

4. The filter circuit according to the preceding claim,

wherein the parallel Shunt Element (SE) comprises a single port SAW resonator.

5. Filter circuit according to one of the preceding claims,

wherein the Notch Filter (NF) comprises a single-port SAW resonator having a transducer with two bus bars and a plurality of transducer fingers alternately connected to one of the two bus bars;

wherein a finger spacing between centers of two adjacent transducer fingers defines a stop band frequency within the Notch Band (NB);

wherein the transducer of the single-port SAW resonator comprises a plurality of different fingerpitches (d 1.. dx.. dn.) and, thus, a number n of different shunt elements having respective stop band frequencies.

6. The filter circuit according to the preceding claim,

wherein the transducer comprises each finger pitch only once, such that each pair of adjacent fingers has a different distance.

7. A PAMiD front-end module (FEM) comprising a filter circuit, a Power Amplifier (PA), and a matching circuit according to one of the preceding claims, wherein the other filter circuit operating in an adjacent band is part of the PAMiD front-end module or a different device operating with the PAMiD front-end module;

wherein the Notch Band (NB) is centered on the adjacent band.

8. The PAMiD front-end module of the preceding claim,

wherein the filter circuit and the further filter circuit are band pass filters and are part of a duplexer or a multiplexer, wherein the Notch Band (NB) assigned to a filter circuit is centered around the useful band of the respective other filter circuit of the duplexer or multiplexer.

9. The PAMiD front-end module of the preceding claim,

wherein the filter circuit is a Tx filter of a duplexer,

wherein the Notch Band (NB) conforms to the useful band of the Rx filter of the same duplexer.