High isolation RF switch with notch filter structure

Abstract

The invention discloses a high-isolation radio frequency switch with a trap structure, which comprises a basic matching single-pole single-throw radio frequency switch unit and a bridge T-shaped trap unit. The present invention adds resistance R7b, bonding wire parasitic inductance L2b, bonding wire parasitic inductance L4b and inductance L3b on the basis of the basic matched single-pole single-throw radio frequency switch unit. When the RF switch is in the off state, the inductance L2b+3b+4b formed in series with the inductance L2b, the inductance L4b and the inductance L3b and the parasitic capacitance formed between the source and the drain of the MOS transistor M1b and the MOS transistor M2b in the off state, The parasitic resistance formed between the source and the drain when the MOS transistor M4b is in the on state and the resistance R7b form a bridge T-shaped trap structure. By adjusting the value of the bridge T-shaped trap resistor R7b and inductor L3b, the required suppression frequency can be determined in a targeted manner. Using this topology can obtain 10-15dB higher isolation than traditional RF switches in the selected frequency band.

Description

technical field [0001] The invention relates to a radio frequency switch, in particular to a high-isolation radio frequency switch with a wave trap structure, which is directly applied to the field of various radio frequency switches in microwave ICs. Background technique [0002] RF switch is a control device used to control the transmission path of radio frequency signals. It is a key component for electronic systems such as communications to achieve high performance. It is widely used in military fields such as communication systems, radar, and electronic countermeasures. With the increase of complex characteristics of information transmission, the requirements for isolation, working bandwidth, and integration of radio frequency switches are also increasing. [0003] Traditional RF switches such as figure 1 As shown, due to the limitation of the standard CMOS / BiCMOS process, the reference ground of the RF switch needs to be connected to the ground through the bonding wir...

AI Technical Summary

Problems solved by technology

However, due to the high cost, high control level, and low integration of the GaAs / GaN process, its application is greatly restricted as the signal processing system is increasingly developed towards low price, low voltage, and integration.

[0005] Under standard process conditions, in order to improve the isolation of RF switches, the method of increasing the series and parallel FET transistor stages of RF switches is generally used. This method increases the complexity of the RF switch mechanism and not only increases the layout area of ​​the circuit. Moreover, due to the increase in the number of series and parallel FET transistor stages on the signal path, a series of problems such as increased insertion loss, narrowed operating bandwidth, and poor input / output standing wave coefficient

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