Differential radio frequency switch circuit

Abstract

The invention discloses a differential radio frequency switch circuit which comprises a first NMOS (N-channel Mental-oxide-semiconductor) pipe, a second NMOS pipe, a third NMOS pipe and a fourth NMOS pipe, wherein a drain electrode of the first NMOS pipe is connected with a source electrode of a second NMOS pipe, and a drain electrode of the third NMOS pipe is connected with a source electrode of the fourth NMOS pipe; a grid electrode of the first NMOS pipe is connected with a grid electrode of the third NMOS pipe, and a grid electrode of the second NMOS pipe is connected with a grid electrode of the fourth NMOS pipe; a pinch-off point of the first NMOS pipe, a pinch-off point of the second NMOS pipe, a pinch-off point of the third NMOS pipe and a pinch-off point of the fourth NMOS pipe are all connected with the ground; a source electrode of the first NMOS pipe is connected with an LNA (low-noise amplifier) interface, and a drain electrode of the second NMOS pipe is connected with a PA (power amplifier) interface; and the grid electrode the first NMOS pipe and the grid electrode of the third NMOS pipe are connected with a resistor R1, and the grid electrode of the second NMOS pipe and the grid electrode of the fourth NMOS pipe are connected with a resistor R2. The differential radio frequency switch circuit provided by the invention adopts a full NMOS design, a gate is connected in series with the resistors, the influence of capacitance on each MOS pipe on a radio-frequency signal can be effectively reduced, meanwhile, the series resistors isolates noises, and the integral radio frequency loss of the circuit is within 0.5dB.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits and relates to a differential radio frequency switch circuit. Background technique [0002] In a wireless or mobile communication system, a radio frequency switch (RF switch) is often used to select a radio frequency channel. For example, radio frequency switches are used to select the receiving and transmitting channels, so as to realize the reception and transmission of wireless signals under the condition of sharing the antenna; in order to increase the anti-jamming performance in military broadband radio stations, radio frequency switches are used to select filters of different frequency bands. In these systems, RF switches are generally required to have as low a drop loss and high isolation as possible. Due to the non-ideality of the switching device, the RF switching circuit has a certain insertion loss and the isolation is limited. It is difficult to achieve high isolation cha...

AI Technical Summary

Problems solved by technology

Although the switching circuit can improve the input / output power characteristics on the basis of the conventional RF switching circuit, its circuit loss is still above 0.5dB

[0004] In addition, there is a parallel distributed field effect transistor method, which is more complicated and requires special design of semiconductor switching devices

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