Transformer feed-back quadrature voltage controlled oscillator and communication apparatus using same

Abstract

A transformer feed-back quadrature voltage controlled oscillator (QVCO) is provided, and the QVCO comprises a first half circuit and a second half circuit, and the first half circuit and the second half circuit respectively comprise a first coupling capacitor, a second coupling capacitor, an induction inductor, a PMOS transistor, an NMOS transistor and a frequency modulation circuit. Base electrodes of the PMOS transistor and the NMOS transistor are respectively connected to a first end of the first coupling capacitor and a first end of the second coupling capacitor. The drain electrode of thePMOS transistor is connected with the first end of the induction inductor, the grid electrode of the NMOS transistor is connected to the drain electrode of the PMOS transistor, and the drain electrode of the NMOS transistor is connected to the grid electrode of the PMOS transistor and the second end of the induction inductor. The frequency modulation circuit is connected to the drain electrode ofthe PMOS transistor and the drain electrode of the NMOS transistor.

Description

technical field [0001] The invention relates to the field of electronic circuits, in particular to a transformer feedback quadrature voltage-controlled oscillator. Background technique [0002] With the development of wireless communication technology, household communication devices are gradually replaced by mobile communication devices, such as smart phones and tablet computers. In addition, communication devices can be installed in smart home appliances, so that wireless data transmission can be performed, thus entering a new era of Internet-of-thing (IOT). [0003] Wireless communication usually completes the receiving and sending of signals by transmitting receivers. The transmit receiver has a frequency synthesizer to convert the wave frequency of the carrier. For the requirement of high communication quality, a stable and accurate local oscillating (LO) signal is urgently needed. The LO signal allows the precise transmission of the wireless signal to the wireless r...

AI Technical Summary

Problems solved by technology

[0005] However, the coupling network of the traditional transformer-feedback quadrature voltage-controlled oscillator is connected to its output terminal, which increases the load on the output, thus reducing the maximum operating frequency

In addition, the current variation coupling will cause a phase offset when operating at different frequencies due to the ultra-wide operating frequency band.

Images