Band domain intragroup delayed flat circuit and distortion compensation amplifier

Abstract

An in-band group delay equalizer is formed in a simple circuit configuration so as to have a flat group delay characteristic over a wide frequency band without having a peak of group delay near each passband edge. The in-band group delay equalizer includes a plurality of convex group delay circuits. Each convex group delay circuit is formed of one hybrid coupler and two resonators connected to respective divided output ports of the hybrid coupler. The center frequencies of the respective convex group delay circuits are set to be different from each other so that the overall group delay characteristic of the in-band group delay equalizer becomes flat. The bandwidth and the group delay can be easily adjusted. A distortion compensation amplifier with very low distortion can be realized using such an in-band group delay equalizer

Description

technical field [0001] The invention relates to an in-band group delay flattening circuit and a distortion compensating amplifier used in a high frequency band. Background technique [0002] In recent years, for the miniaturization of base stations, the use of distortion compensation amplifiers has been increasing in base station wireless devices of mobile communication systems. [0003] As a distortion compensation circuit, for example, a feedback amplifier is used, and in the distortion detection circuit and the distortion suppression circuit, it is necessary to make the group delay times equal between the high-power side and the low-power side. At first, coaxial lines (cables) were used for this purpose, but in recent years, delay filters have been used for miniaturization and loss reduction. [0004] Of course, the flatness of the group delay time (the degree to which the group delay time variation is small) within the passband is required for the delay filter. In the ...

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Problems solved by technology

Therefore, when adjusting the group delay time in the process of mass production, since the adjustment is difficult and time-consuming, there is a problem.

[0012] Also, the above-mentioned parallel capacitance for transition coupling is smaller than the capacitance for coupling between adjacent resonators, so it is not affected by Figure 17 The influence of stray capacitance other than the electrostatic capacitance shown in the equivalent circuit is large, and there is also a problem that the characteristic dispersion increases during manufacturing.

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