Radio frequency receiver based on carrier enhancement technology

Abstract

The invention discloses a radio frequency receiver based on a carrier enhancement technology, and belongs to the technical field of electronic circuits. The radio frequency receiver comprises an antenna, an alternating current source, a time-varying transmission line, a duplexer, a 50-Ohm load, a direct current bias, a low-noise amplifier and a power amplifier, wherein an upper transmission line of the time-varying transmission line is used for transmitting a receiving signal and an emitting signal; a lower transmission line of the time-varying transmission line transmits a carrier wave; the two transmission lines are connected in parallel with an abrupt junction variable capacitance diode group in an equal spacing manner to perform frequency mixing on the carrier wave and the receiving signal; the lower transmission line and the ground are connected in parallel with an MOS (Metal Oxide Semiconductor) variable capacitance diode group in an equal spacing manner to increase an amplitudevalue of the carrier wave. The radio frequency receiver based on the carrier enhancement technology, which is disclosed by the invention, can realize a high gain within a relatively wide frequency band of the receiving signal, solves the problem of loss caused after a conventional time-varying transmission line enters a high frequency, reduces a requirement of a backward-stage duplexer, and in addition, reduces backward-stage noise, thereby improving the overall noise of a system.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and more specifically relates to a radio frequency receiver based on a carrier strengthening technology. Background technique [0002] The high isolation and low noise of the time-varying transmission line using the distributed modulation capacitor (DMC) structure shows the potential advantages of being applied in the front end of a full-duplex transceiver. In a time-varying transmission line, the antenna receives and transmits signals at the same frequency but in different directions of propagation. The signal received from the antenna is modulated by the carrier during transmission to the transmitter because the propagation direction is in the same direction as the carrier; while the transmitted signal is directly transmitted to the antenna because the propagation direction is reversed, causing only little interference to the DMC. The varactor diodes connected in parallel at equal ...

AI Technical Summary

Problems solved by technology

However, when the traditional time-varying transmission line is at low frequency, the frequency conversion gain is positive. When the frequency reaches 0.6GHz, the frequency conversion gain is negative. As the frequency further increases, the frequency conversion loss increases

Although the passive network has the advantage of low noise, as far as the noise of the overall system is concerned, when the frequency conversion gain is continuously reduced or even negative, the noise of the subsequent stage is amplified, thereby increasing the overall noise

For the above problems, there is a way to feed back the received signal at the output end to the input end, but it can only achieve high gain in a narrow band

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