Numerical control LC voltage controlled oscillator with amplitude detection

Abstract

The invention discloses a numerical control LC voltage controlled oscillator with amplitude detection. The numerical control LC voltage controlled oscillator comprises an LC oscillator and an oscillation signal amplitude detection unit. The LC oscillator is composed of an LC frequency resonant unit, a capacitor array unit and a varactor array unit; and an output amplitude detection unit is composed of a differential amplification circuit with a tail current source and a transmission gate with a switch controller. The LC voltage controlled oscillator generates a high-performance and low-noise differential oscillation signal, and changes the bandwidth and the voltage control gain through a numerical control signal provided by an external circuit. The output amplitude detection unit receives an oscillated high-frequency differential signal and outputs the maximum value of the differential signal, and the amplitude of an oscillation signal can be obtained by subtracting a DC offset from the maximum value. The numerical control LC voltage controlled oscillator disclosed by the invention can not only realize a large variable capacitance range and a highly linear voltage control gain, and can further judge whether the circuit can perform normal oscillation work, obtain the amplitude of the high-frequency oscillation signal, and solve the problem of monitoring the oscillation circuit and the oscillation signal in real time.

Description

technical field [0001] The invention belongs to the technical field of CMOS integrated circuits, and in particular relates to an LC voltage-controlled oscillator with amplitude detection. Background technique [0002] With the rapid development of information technology, wireless communication network has been widely used. In a wireless communication system, the radio frequency receiver is located at the forefront of the entire system. The phase-locked loop frequency synthesizer plays a very important role in providing the local oscillator signal required for frequency conversion of the receiver in the radio frequency receiver, and generates different center frequencies according to the channel planning. With the increasing development of electronic systems, the phase-locking The technical requirements are also getting higher and higher. The current phase-locked loop (PLL) chip is developing in the direction of high frequency, wide frequency bandwidth, large integration, l...

AI Technical Summary

Problems solved by technology

[0004] In the literature titled "9-11GHz Digitally Controlled LC Oscillator" (Research and Progress in Solid-State Electronics, 2013, 33(3): 265-269, 293), Liu Junren et al. proposed an all-digital frequency synthesizer, frequency The digitally controlled LC oscillator with a coverage range of 8.95 to 11.02GHz adopts a complementary LC oscillator structure with tail inductors and contains 3 sets of programmable capacitor arrays to cooperate with the 3 frequency locking processes of the digital frequency synthesizer. At the same time, a filter circuit composed of capacitors and inductors is used to replace the tail current source and connect to the power supply to improve the phase noise of the circuit, but it brings a sharp increase in the layout area. In addition, the frequency coarse adjustment variable capacitor given by it The parasitic effect of the three switching tubes in the way is large, and how to achieve a large variable capacitance range and step is not given

[0005] Wu Zhaohui and others also proposed a numerically controlled minimum variable capacitance in a document titled "Numerical Controlled LC Oscillator Based on Minimum Variable Capacitance Structure" (Huazhong University of Science and Technology Journal of Natural Sciences, 2016, 44(5):76-80). The structure of the LC oscillator, which uses a complementary varactor across both ends of the fixed capacitance structure, can use a larger size varactor to achieve a smaller varactor value, thereby reducing the impact of process errors on the design results, and at the same time It solves the nonlinear problem under the large-swing oscillation signal, and alleviates the influence of the mismatch capacitor on the consistency of the mismatch rate on the minimum varactor value, but there is no description in the literature on how to implement various capacitor arrays

Images