Regenerative frequency divider of broadband topological structure

Abstract

The invention discloses a regenerative frequency divider of a broadband topological structure. The regenerative frequency divider comprises a first all-pass filter, a second all-pass filter, a third all-pass filter, a fourth all-pass filter, a first frequency mixer, a second frequency mixer and a power synthesizer. Orthogonal mode driving is achieved through the two frequency mixers and the feedback ends of the input port and the output port through the first all-pass filter, the second all-pass filter, the third all-pass filter and the fourth all-pass filter respectively, so that single side band conversion (SSB) is achieved, and signals output by the two frequency mixers are synthesized through the power synthesizer. And the unnecessary upper single frequency is eliminated, and only the lower side band frequency is left. Therefore, the lower frequency is not limited by the upper side band frequency and is only limited by the bandwidth of the all-pass filter, so that the regenerative frequency divider with a broadband topological structure is provided.

Description

technical field [0001] The invention relates to a frequency divider, in particular to a regenerative frequency divider with broadband topological structure. Background technique [0002] A frequency divider has been widely used in modern communication equipment. By dividing the frequency of a clock signal with a certain frequency, another signal with a lower frequency than the clock signal is obtained. Among them, the commonly used frequency dividers are: varactor frequency divider, digital frequency divider and regenerative frequency divider, and compared with varactor frequency divider and digital frequency divider, regenerative frequency divider has more superior phase noise performance. [0003] The basic circuit of a regenerative frequency divider is as figure 1 As shown, the principle is: under appropriate conditions, mixing the input signal and the output signal produces 1 / 2 at the output of the mixer f in and 3 / 2 f The two signal components of in are filtered by ...

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Problems solved by technology

[0004] However, the frequency range of the regenerative frequency divider is limited, due to the existence of the low-pass filter LPF, 1 / 2 f The frequency of the in signal component must lie within the passband of the low-pass filter, while 3 / 2 f The frequency of the in signal component must lie outside the passband of the low-pass filter if 3 / 2 of the mixer output f The frequency of the in signal component falls within the passband of the low-pass filter, 1 / 2 of which f in signal components will also be limited

Although, the mixer uses double-sideband conversion (DSB), that is, one of the two conversion sidebands is used and the other is wasted, that is, half of the conversion power is lost, resulting in a 3 dB reduction in SNR. This SNR The loss cannot be recovered by any amount of post-mixer gain and will have an impact on other subsequent circuits

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