Medium and high frequency multi-mode frequency division ratio adjustable lo fractional frequency divider

Abstract

The invention provides a medium high frequency multi-mode frequency dividing ratio adjustable LO fractional divider, comprising a / 2 integer frequency divider, a waveform adjusting circuit connected to the / 2 integer frequency divider, a downsampling device connected to the waveform adjusting circuit, a digital logic circuit, a phase alignment module, wherein the input end of the phase alignment module is connected to the digital logic circuit and the waveform adjusting circuit and the output end of the phase alignment module is connected to the downsampling device, and a multi-path phase signal combination circuit connected to the downsampling device. medium high frequency multi-mode frequency dividing ratio adjustable LO fractional divider adjusts a level of a counter which accesses to a circuit through a switch, generates random N / 2 (N=3,5,7...) frequency dividing ratio signals, and is more flexible in adjustment. Besides, the medium high frequency multi-mode frequency dividing ratio adjustable LO fractional divider greatly saves the area of the circuit through repeated use of devices.

Description

technical field [0001] The invention belongs to the technical field of wireless communication integrated circuits, in particular to a mid-high frequency multi-mode frequency division ratio adjustable LO fractional frequency divider. Background technique [0002] With the advancement and development of wireless communication technology, transceivers have increasingly stringent requirements on local oscillator signals (Local Oscillator, LO). On the one hand, in order to make the transceiver applicable to different communication protocols in various frequency bands, the local oscillator signal needs to have a large frequency coverage. On the other hand, since more and more RF system modules are integrated on the same chip, This makes the local oscillator signal more and more seriously interfered by other modules. Wherein, when the frequency of the power amplifier (PA) and the VCO (Voltage Control Oscillator, VCO) are close, a VCO pulling effect will occur, which will cause a d...

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Problems solved by technology

[0006] Aiming at the above-mentioned deficiencies in the prior art, the present invention proposes a mid-high frequency multi-mode frequency division ratio adjustable LO fractional frequency divider, which is used to solve the LO fractional frequency divider in the prior art due to its own limited image interference suppression The problem of the need to add an additional large-area inductor for filtering due to the ability of the filter, and the problem of limited frequency division ratio range and difficult to eliminate glitches due to the regular selection of signals of different phases through the selector

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