LC wave band high-temperature superconducting frequency division filter

Abstract

A Lamp; the C-band high-temperature superconducting frequency division filter comprises a three-port matching network, an L-band filter and a C-band filter which are arranged on a dielectric substrate, the filter is characterized in that the three-port matching network is of a similar T-shaped structure and is composed of stepped impedance multi-fold microstrip lines, a resonator of the L-band filter is of a similar hairpin-shaped structure with capacitive finger tip loading, the two ends of the resonator are parallel branch microstrip lines in a left-right hand interdigital shape, a resonator of the C-band filter is of a hairpin-shaped structure, and the two ends of the C-band filter are parallel branch microstrip lines in a right-left hand interdigital shape. Microstrip circuits of the three-port matching network, the L-band filter and the C-band filter are made of high-temperature superconducting thin film materials; the three-port matching network has the advantages that the three-port matching network can organically combine an L-band filter and a C-band filter, frequency division filtering of L-band and C-band signals is achieved, a hairpin-like structure loaded at a capacitive finger tip is introduced, equivalent capacitance is increased, frequency multiplication of the L-band filter is pushed out of the C-band, and the three-port matching network has the advantages of being compact in structure, high in frequency selectivity, low in cost and the like. And the isolation degree is good.

Description

(I)TECHNICAL FIELD

[0001] The utility model relates to high temperature superconducting filter technical field and microwave communication field, especially a kind of L&C waveband high temperature superconducting frequency division filter. (II)BACKGROUND

[0002] With the rapid development of electronic technology and communication technology, microwave filter is the key component in communication, radar, navigation and other systems, and plays an increasingly important role in signal processing field. The development of communication technology application also makes the spectrum resource increasingly crowded, and the increase of signals in each frequency band makes the electromagnetic environment more complex, and the interference between adjacent frequency signals usually leads to the reduction of communication base station coverage, the reduction of communication capacity and the deterioration of communication quality. In the frequency band where various signals such as television and radio are concentrated, it is often necessary to separate the signals in a wide frequency range into several frequency ranges for receiving the required signals. The initial scheme is to use power divider to allocate power and receive signals, which divides the energy of one input signal into two or more output signals. Power divider can be used for a set of antennas to connect multiple microwave receivers. Since power divider is used for power allocation, the receiver receives signals with unavoidable energy attenuation, and the signals received by the receiver are the entire wide frequency domain signals, resulting in poor signal-to-noise ratio. The noise between signals cannot be isolated in the power divider, so even if the signal allocation is achieved, the receiver receives signals with large noise, which cannot meet the needs of modern communication. Another scheme is to use frequency division scheme to process frequency division of signals, use circulator and multiple filters in cascade to realize step-by-step frequency division output of each frequency band signal, but this scheme needs to cascade multiple filters, the circuit structure is too complex, it is not easy to tune, and the isolation between signals in each frequency band is poor. With the continuous deepening of frequency division technology research and the development of high temperature superconducting material and manufacturing technology, researchers apply it to radio frequency circuit, find that the surface resistance of superconducting material is about 2-3 orders of magnitude lower than that of traditional metal material in radio frequency / microwave frequency band, and has very high quality factor. The utility model applies high temperature superconducting material to frequency divider microstrip circuit design, and designs a kind of L&C waveband high temperature superconducting frequency division filter, which connects two bandpass filters of different frequency bands with three-port matching network, can divide input signals into one low-frequency signal and one high-frequency signal output, to achieve good frequency division requirements, so that the isolation between two signals is higher and the selectivity is better. (III)SUMMARY

[0003] The utility model wants to solve the problem in prior art, provide a kind of L&C wave band high-temperature superconducting frequency division filter, adopt high-temperature superconducting thin film material, simultaneously work in L and C two frequency bands, realize one input two output.It can be applicable to current complex electromagnetic environment, realize the frequency division filtering of L and C two wave bands, while the interference signal of L and C wave band intermediate wave band can be suppressed, signal isolation degree is high, signal selectivity is good, can share the same input antenna, two outputs are respectively connected different frequency band receiver, with low loss, small, compact structure, design flexible etc.

[0004] The utility model solves the technical scheme that technical problem thereof adopts:

[0005] A kind of L&C wave band high-temperature superconducting frequency division filter, including three-port matching network, L wave band filter and C wave band filter on dielectric substrate;Its characterized in that, three-port matching network is T-shaped structure, is made of stepped impedance multi-fold microstrip line, one end is input terminal, other two ends are connected with L wave band filter and C wave band filter respectively, the resonator of L wave band filter is the hairpin-like structure of capacitive finger end loading, the parallel branch microstrip line of left and right hand interdigital is at the two ends of resonator, to increase the equivalent capacitance of resonator and push high L wave band filter frequency, resonator is coupled through gap between each other, the order is 3 to 50 order, the resonator of C wave band filter is hairpin-like structure, resonator is coupled through gap between each other, the order is 3 to 50 order, the microstrip circuit of three-port matching network, L wave band filter and C wave band filter is made of high-temperature superconducting thin film material.

[0006] The dielectric substrate material is magnesium oxide, lanthanum aluminate or sapphire, when the dielectric substrate is magnesium oxide substrate, the dielectric constant is 9.7.

[0007] The microstrip line width and length of the three-port matching network connected with L wave band filter and C wave band filter are different.

[0008] The input terminal of the three-port matching network is the input terminal of L&C wave band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

[0009] The output terminal of the L wave band filter is the L wave band output terminal of L&C wave band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

[0010] The output terminal of the C wave band filter is the C wave band output terminal of L&C wave band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

[0011] The utility model relative to prior art's advantages and effects are:

[0012] The three-port matching network in the microstrip circuit is a T-shaped structure, which is composed of a stepped impedance multi-fold microstrip line, one end of which is an input end, and the other two ends are connected with an L-band filter and a C-band filter respectively, the microstrip lines connected with the L-band filter and the C-band filter are different in width and length, the use of the matching network can make the L-band filter and the C-band filter organically combined and well matched, so that the interference between the signals is extremely low, the signal isolation degree is high, the resonator structure of the L-band filter is a hairpin-shaped structure loaded with capacitive fingers, and the two ends of the resonator are left-handed and right-handed interdigital parallel branch microstrip lines, so that the equivalent capacitance of the resonator is increased and the frequency multiplication of the L-band filter is increased, so that the L-band filter will not interfere with the passband filtering effect of the C-band filter, the two resonators of the L-band and the C-band are symmetrical structures, and the above structure makes the L&C band high-temperature superconducting frequency division filter of the present application have the advantages of high isolation degree, small loss, compact structure, flexible design, high frequency selectivity, small size and the like compared with the traditional scheme. (IV) DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be introduced below.

[0014] Figure 1 It is an overall structure schematic diagram of the L&C band high-temperature superconducting frequency division filter.

[0015] Figure 2 It is a three-port matching network unit structure schematic diagram of the L&C band high-temperature superconducting frequency division filter.

[0016] Figure 3 It is an L-band filter single resonator structure schematic diagram of the L&C band high-temperature superconducting frequency division filter.

[0017] Figure 4 It is a C-band filter single resonator structure schematic diagram of the L&C band high-temperature superconducting frequency division filter.

[0018] Figure 5 It is a frequency response curve of the L&C band high-temperature superconducting frequency division filter.

[0019] Figure 6 It is an overall structure schematic diagram of the L&C band high-temperature superconducting high-order frequency division filter.

[0020] In the drawings, 00 is an L&C band high-temperature superconducting frequency division filter, 101 is a three-port matching network, 102 is an L band filter, 103 is a C band filter, 104 is a stepped impedance multi-fold microstrip line, 105 is an L band filter resonator structure, 106 is a left-right hand interdigital parallel stub microstrip line, 107 is a C band filter resonator structure, 108 is a magnesium oxide dielectric substrate, 200 is an L&C band high-temperature superconducting high-order frequency division filter, 201 is an L band high-order filter, 202 is a high-order C band filter, 203 is a three-port matching network of an L&C band high-temperature superconducting high-order frequency division filter, and 204 is a lanthanum aluminate dielectric substrate.

[0021] Embodiment 1

[0022] An L&C band high-temperature superconducting frequency division filter 100 comprises a three-port matching network 101, an L band filter 102 and a C band filter 103 arranged on a magnesium oxide dielectric substrate 108, wherein the three-port matching network 101 is a T-shaped structure and is composed of a stepped impedance multi-fold microstrip line 104, one end of which is an input end, and the other two ends are connected to the L band filter 102 and the C band filter 103 respectively, the L band filter resonator structure 105 is a hairpin-like structure with capacitive finger loading, and the resonators are connected by left-right hand interdigital parallel stub microstrip lines 106 at both ends to increase the equivalent capacitance of the resonators and the frequency multiplication of the L band filter, the resonators are coupled by gaps, and the order is 12, the C band filter resonator structure 107 is a hairpin-like structure, the resonators are coupled by gaps, and the order is 12, and the microstrip circuits of the three-port matching network 101, the L band filter 102 and the C band filter 103 are made of high-temperature superconducting thin film materials.

[0023] The dielectric substrate is a magnesium oxide substrate 108, and the dielectric constant is 9.7.

[0024] The microstrip line widths of the three-port matching network 101 connected to the L band filter 102 and the C band filter 103 are different, and the lengths are different.

[0025] The input end of the three-port matching network 101 is the input end of the L&C band high-temperature superconducting frequency division filter 100, and the characteristic impedance is 50 ohms.

[0026] The output end of the L band filter 102 is the L band output end of the L&C band high-temperature superconducting frequency division filter 100, and the characteristic impedance is 50 ohms.

[0027] The output end of the C band filter 103 is the C band output end of the L&C band high-temperature superconducting frequency division filter 100, and the characteristic impedance is 50 ohms.

[0028] AsFigure 5 As shown in the figure, the frequency response curve of the L&C band high-temperature superconducting frequency division filter 100, the frequency response curve of S12 has an insertion loss less than 0.1 dB in the L band passband, and an isolation better than 55 dB for C band signals, the frequency response curve of S13 has an insertion loss less than 0.1 dB in the C band passband, and an isolation better than 65 dB for L band signals, the isolation between the two frequency bands is high, the selectivity of the signal passing is good, and the frequency division filtering requirements for L band and C band signals can be met.

[0029] Embodiment 2

[0030] An L&C band high-temperature superconducting high-order frequency division filter 200, comprising a three-port matching network 203, an L band high-order filter 201 and a C band high-order filter 202 arranged on a lanthanum aluminate medium substrate 204; characterized in that the order of the L band high-order filter 201 is 14, and the order of the C band high-order filter 202 is 16.

[0031] The L&C band high-temperature superconducting high-order frequency division filter 200, characterized in that the three-port matching network 203 of the L&C band high-temperature superconducting high-order frequency division filter is a T-shaped structure microstrip line composed of a stepped impedance multi-fold microstrip line, one end is an input end, and the other two ends are connected with the L band high-order filter 201 and the C band high-order filter 202 respectively, the connected microstrip lines have different widths and lengths, and the two filters are matched by using the stepped impedance structure and the multi-fold microstrip line.

[0032] The L&C band high-temperature superconducting high-order frequency division filter 200, characterized in that the medium substrate is a magnesium oxide medium substrate 204 with a dielectric constant of 23.6.

[0033] In this embodiment 2, the order of the two filters is increased, so that the isolation of the entire high-order frequency division filter is improved and the signal selectivity is increased.

Claims

1. An L&C band high temperature superconducting frequency division filter comprising a three-port matching network, an L band filter and a C band filter provided on a dielectric substrate; characterized in that, The three-port matching network is a T-shaped structure, which is composed of stepped impedance multi-fold microstrip lines, one end of which is an input end, and the other two ends are connected with an L-band filter and a C-band filter respectively, the resonator of the L-band filter is a hairpin-shaped structure loaded with a capacitive finger end, the resonator is a left-handed and right-handed interdigital parallel branch microstrip line, the resonators are coupled through gaps, the order is 3-50, the resonator of the C-band filter is a hairpin-shaped structure, the resonators are coupled through gaps, the order is 3-50, and the microstrip circuits of the three-port matching network, the L-band filter and the C-band filter are made of high-temperature superconducting thin film materials.

2. A high temperature superconducting frequency division filter for L&C bands according to claim 1, characterized in that The medium substrate material is magnesium oxide, lanthanum aluminate or sapphire, and the dielectric constant of the magnesium oxide substrate is 9.

7.

3. A high temperature superconducting frequency division filter for L&C bands according to claim 1, characterized in that The microstrip line widths and lengths of the three-port matching network, the L-band filter and the C-band filter are different.

4. A high temperature superconducting frequency division filter for L&C bands according to claim 1, characterized in that The input end of the three-port matching network is the input end of the L&C band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

5. A high temperature superconducting frequency division filter for L&C bands according to claim 1, characterized in that The output end of the L-band filter is the L-band output end of the L&C band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

6. A high temperature superconducting frequency division filter for L&C bands according to claim 1, characterized in that The output end of the C-band filter is the C-band output end of the L&C band high-temperature superconducting frequency division filter, and the characteristic impedance is 50 ohms.

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