Cavity filter structure mathematical response model and cavity filter for mobile communication network thereof

Abstract

The invention relates to a cavity filter used for a microwave communicating system. Aiming at solving the technical problems of disunited structure size and complex structure of the existing cavity filter manufactured by a Chebyshev mathematics response model, the invention provides a mathematics response model of a cavity filter structure and a cavity filter used for a movable communicating network; the mathematics response model thereof adopts an isoparametric element lowpass prototype as the designed mathematics response model of the cavity filter structure and leads the cavity filter structure obtained according to the mathematics response model to respectively have united and consistent structure sizes on the resonance cavity, resonance rod, coupling adjusting rod and resonance cavity clapboard thereof, thus leading the product manufacturing and processing technique of the cavity filter to be greatly simplified; simultaneously the assembled cavity filter is easier to be debugged and is suitable for batch production. Another advantage of the technical scheme is as follows: under the condition of meeting stopband attenuation, the central loss of a benchmark passband is reduced to the minimum; moreover, the unloaded Q value of the cavity can be guaranteed to be maximal and the insertion loss of the cavity filter is minimal.

Description

technical field [0001] The invention relates to a band-pass filter, a component of a microwave communication system, and in particular to a cavity filter for a mobile communication network. Background technique [0002] In the mobile communication network, especially in the current 3G mobile communication network, the filter plays a very important role, and it is required to have the characteristics of low insertion loss and high selectivity. Taking the construction of TD-SCDMA base station as an example, since TD-SCDMA uses a smart antenna with a relatively complex structure, the nonlinearity will exceed that of other ordinary base station antennas, so the low noise increase of TD-SCDMA affected by electromagnetic effects will be higher than that of ordinary base stations. Therefore, a large number of band-pass filters with low insertion loss and high selectivity are required in the uplink and downlink of the base station. In order to meet the high requirements of the mobi...

AI Technical Summary

Problems solved by technology

Most of these cavity filters are designed and manufactured with Chebyshev as the mathematical response model. Since the unloaded Q value of the actual cavity filter is limited, the application of the Chebyshev mathematical response model must be carried out by pre-distortion design. In this way, the insertion loss in the center of the passband increases, so it is difficult to meet the requirements of signal transmission and interference suppression required for the uplink and downlink of the base station in the TD-SCDMA network

In particular, some technical problems in the cavity filter manufactured by the Chebyshev mathematical response model are fatal: the coupling capacitance of the resonant circuit is not equal, the inductance of the resonant circuit is not equal, and the coupling amount of each circuit is not uniform. The size and adjustment are not uniform, and the structure is complex, which greatly increases the complexity and difficulty of processing and debugging

Images