CN204168257U - A kind of wideband microband amplitude equalizer - Google Patents

Abstract

The utility model discloses a broadband microstrip amplitude equalizer, which includes a resonator, and is characterized in that the resonator is a transmission line resonator, and the transmission line resonator includes a main transmission line, a thin film resistor and a microstrip line. The main transmission line is provided with the thin film resistor and the microstrip line, the thin film resistor is connected to the microstrip line, and the transmission line resonator is composed of a TEM transmission line segment, and the TEM transmission line segment is an open line . The utility model can effectively compensate the amplitude-frequency inconsistency of the whole system due to the loss of transmission cables, frequency converters, amplifiers and other devices, especially the phenomenon that the loss increases with the increase of frequency in the process of microwave signal transmission and amplification; it can also effectively Improve the large amplitude unevenness that will be generated in the AD/DA process when the signal is processed by the intermediate frequency signal, and the equalization of the RF end after the signal is up-converted is better than the equalization at the DA intermediate frequency output end, which can ensure a good phase flatness.

Description

A Broadband Microstrip Amplitude Equalizer

technical field

The utility model relates to a broadband microstrip amplitude equalizer, which belongs to the technical field of communication.

Background technique

With the development of microwave materials and process technology, the bandwidth of microstrip switches, amplifiers, mixers and other devices has become wider and wider, but for transmission characteristics such as gain and insertion loss, due to the microwave signal transmission loss and signal wavelength Related, the gain or insertion loss of the device is difficult to achieve exactly the same in the low frequency end and high frequency end. In practical engineering applications, the amplitude-frequency characteristics of broadband microwave devices fluctuate. Usually, the gain decreases with the increase of frequency, and there are fluctuations in the frequency range. In addition to the standing wave matching problem of the external components, the microwave components The composed broadband microwave receiver must have large fluctuations, which will reduce the signal-to-noise ratio of the detected signal, thereby affecting the receiving sensitivity of the system.

There are four types of equalizers: lumped parameter type, coaxial type, waveguide type and integrated transmission line type. The lumped parameter type is limited by components and is generally used in low frequency bands, not suitable for high frequency bands; the coaxial microwave equalizer is generally used for high-power circuit equalization; the waveguide type is suitable for high-end microwave frequencies; and the integrated transmission line microwave The equalizer has the advantages of small size, light weight, and easy integration with solid-state circuits. In addition, this integrated transmission-line equalizer can be simulated quickly and accurately using microwave circuit simulation technology, shortening the

The amplitude equalizer can effectively compensate the amplitude-frequency inconsistency of the whole system due to transmission cables, frequency converters, amplifiers and other devices, especially due to the phenomenon that the loss increases with the increase of frequency in the process of microwave signal transmission and amplification. Moreover, inserting the amplitude-frequency equalization network at the appropriate position of the radio frequency amplification system of the radar transmitter can effectively improve the gain flatness and make the index meet the requirements, which is beneficial to the realization of the overall system index.

Utility model content

In order to overcome the defects in the prior art and solve the above-mentioned technical problems, the utility model provides a broadband microstrip amplitude equalizer.

The utility model adopts the following technical scheme: a broadband microstrip amplitude equalizer, including a resonator, characterized in that the resonator is a transmission line resonator, and the transmission line resonator includes a main transmission line, a thin film resistor and a microstrip line, the main transmission line is provided with the thin film resistor and the microstrip line, the thin film resistor is connected to the microstrip line, the transmission line type resonator is composed of a TEM transmission line segment, and the TEM transmission line segment to open the route.

Furthermore, the number of transmission line type resonators is four.

Furthermore, the transmission line type resonators are matched and cascaded.

Furthermore, the substrate of the microstrip line is a Rogers RT /duroid 5880 substrate with a dielectric constant of 2.2 and a thickness of 0.254mm.

Furthermore, the distance between the microstrip lines is greater than or equal to 4 times the thickness of the substrate.

Furthermore, the width of the microstrip line is 0.3mm.

Furthermore, the main transmission line is a 0.77mm wide 50Ω transmission line.

The beneficial effects achieved by the utility model: (1) It can effectively compensate the amplitude-frequency inconsistency of the whole system due to the loss of transmission cables, frequency converters, amplifiers and other devices, especially because the loss increases with the increase of frequency in the process of microwave signal transmission and amplification. (2) It can effectively improve the amplitude unevenness, and make the frequency-converted signal equalize at the radio frequency end than at the intermediate frequency end, which can ensure good phase flatness.

Description of drawings

Fig. 1 is a schematic diagram of the circuit structure principle of the utility model.

Fig. 2 is a topological diagram of the utility model.

Fig. 3 is a schematic diagram of an embodiment of the present invention.

Fig. 4 is a block diagram of the application of the utility model in the radio frequency source system.

The meaning of the marks in the figure: 1-main transmission line, 2-thin film resistor, 3-microstrip line.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described. The following examples are only used to illustrate the technical solution of the utility model more clearly, but not to limit the protection scope of the utility model.

Fig. 1 is a schematic diagram of the circuit structure principle of the present utility model, which is essentially a single-branch amplitude equalization circuit. On the main transmission line 1, the main equalization part is composed of a section of open-circuit microstrip line 3 and a thin film resistor 2 of about λ/4 , λ is the center frequency wavelength. The open-circuit microstrip line of λ/4 is connected to the thin-film resistor to form a series resonant circuit with adjustable resonant frequency, quality factor, relative bandwidth and equalization. The resonant frequency can be changed by adjusting the open-circuit microstrip line of λ/4; by adjusting the width of the microstrip line and the resistance value of the film resistor, the quality factor and relative bandwidth can be changed, among which the influence of the film resistance is the main one, and the width of the microstrip line The effect is secondary. The longer the resonant stub length, the narrower the bandwidth of the resonator. The equalization quantity is a parameter related to the resonance frequency, quality factor and relative bandwidth. There is no specific formula to calculate it, and it is generally obtained through simulation and optimization.

Fig. 2 shows the topology diagram of the utility model. For a circuit with a large amount of equalization, it is formed by matching and cascading multiple single-node equalization circuits.

As a preferred embodiment, Fig. 3 adopts four single-branch equalization circuit matching cascades, adopts a Rogers RT /duroid 5880 substrate with a thickness of 0.254mm, and its dielectric constant is 2.2. The edge of the microstrip line extends to both sides along the electric field, and the extension distance of the electric field is approximately equal to 2h (h is the thickness of the substrate). Therefore, in order to avoid line-to-line coupling, the distance between the microstrip lines and the distance from the microstrip to the side wall of the outer box should be kept at least 4 times the thickness of the substrate. Since it is difficult to guarantee the dimensional accuracy when the line is less than 0.1 mm, 0.3 mm is selected for the design of the microstrip branch. The main transmission line is a 0.77mm wide 50Ω transmission line.

Fig. 4, as a preferred embodiment, is a block diagram of the application of the utility model in a radio frequency source system. Inserting the amplitude-frequency equalization network at the appropriate position of the radio frequency amplification system of the radar transmitter can effectively improve the gain flatness and make the index meet the requirements, which is beneficial to the realization of the overall system index.

The working principle of the utility model: a micro-broadband amplitude equalizer provided by the utility model can effectively compensate the amplitude-frequency inconsistency of the whole system due to transmission cables, frequency converters, amplifiers and other devices, especially due to microwave signal transmission And the phenomenon that the loss increases with the increase of the frequency during the amplification process; because the AD/DA process will produce a large amplitude unevenness during the signal processing of the intermediate frequency signal, which will affect the signal flatness after the system is up-converted. The newly provided micro-broadband amplitude equalizer can effectively equalize the amplitude unevenness at the radio frequency end, thereby replacing the amplitude equalization at the intermediate frequency end, and can ensure good phase flatness.

The above is only the preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the utility model, some improvements and deformations can also be made. And deformation should also be regarded as the protection scope of the present utility model.

Claims (7)

1. A broadband microstrip amplitude equalizer, comprising a resonator, is characterized in that, the resonator is a transmission line resonator, and the transmission line resonator includes a main transmission line, a thin film resistor and a microstrip line, and the main transmission line The thin-film resistor and the microstrip line are arranged on it, the thin-film resistor is connected to the microstrip line, and the transmission line type resonator is composed of a TEM transmission line segment, and the TEM transmission line segment is an open line. 2. A kind of broadband microstrip amplitude equalizer according to claim 1, is characterized in that, the number of described transmission line type resonator is 4. 3. A wideband microstrip amplitude equalizer according to claim 2, characterized in that said transmission line resonators are matched and cascaded. 4. a kind of broadband microstrip amplitude equalizer according to claim 2, is characterized in that, the substrate of described microstrip line is that dielectric constant is 2.2, and thickness is the Rogers RT /duroid 5880 substrate of 0.254mm . 5. The broadband microstrip amplitude equalizer according to claim 4, wherein the distance between the microstrip lines is greater than or equal to 4 times the thickness of the substrate. 6. A wideband microstrip amplitude equalizer according to claim 5, wherein the width of the microstrip line is 0.3mm. 7. The wideband microstrip amplitude equalizer according to claim 6, wherein the main transmission line is a 0.77mm wide 50Ω transmission line.