An Ultra-Low Power Biased RF Switch

Abstract

The present invention proposes a new radio frequency switch structure: each radio frequency switch includes a series branch and a parallel branch, the series branches through different radio frequency switches share an AC coupling capacitor, the parallel branch and the parallel branch in the same radio frequency switch The series branch shares an AC coupling capacitor, removes the blocking transistor and the AC coupling capacitor close to the ground in the parallel branch of the same radio frequency switch, does not need any negative voltage generating circuit, and can save more than 60% of the capacitor area compared with the traditional structure. The invention greatly reduces the area and cost of the chip while keeping the performance unchanged.

Description

technical field [0001] The invention relates to the field of radio frequency signal processing, in particular to an ultra-low power consumption biased radio frequency switch. Background technique [0002] High-quality RF switches are key components of multi-mode, multi-frequency, and multi-standard wireless RF transceivers, especially in time-division duplex wireless systems, where they play an irreplaceable role. The application of RF switches in the rapidly developing 3G / 4G multi-mode and multi-band terminals is becoming more and more extensive, and the complexity of RF terminals is increasing, especially for the application requirements of "five-mode and thirteen-band" proposed by China Mobile. The demand leads to the use of at least multiple RF switches in the RF terminal to switch between different frequency bands and modes at the data, voice, and diversity receiving ends respectively. As the complexity of the system increases, the usage of switches in the RF system wi...

AI Technical Summary

Problems solved by technology

[0005] However, the SOI radio frequency switch has the following problems: because a high-power input signal often requires a switch drive circuit, wherein the switch drive circuit includes a negative voltage generating circuit, which is used to generate a negative voltage to provide bias for the gate and body in the closed branch. set, such as figure 2 shown

[0007] But there is a problem with the above structure: combining Figure 4 The complete SP4T antenna switch shown shows that the number of capacitors will increase with the increase of the number of throws. Each branch needs four parallel capacitors. Two capacitors are on both sides of the series stacked transistor unit. The other two capacitors are respectively On both sides of the parallel stacked transistor unit, these capacitances are much larger than the parasitic capacitance of the transistor itself to reduce the influence of the nonlinearity of the parasitic capacitance. Therefore, generally these capacitances are implemented with a MIM or MOM structure, which will occupy a large amount of chip area and cause chip Costs have risen sharply

[0008] It can be seen from the above that there is still a need for further improvement in the design of the existing SOI RF switch in terms of power consumption and volume

Images