Skyworks Solutions, Inc.
Apparatus and methods for front-end systems with reactive loopback

Abstract:

Apparatus and methods for front-end systems with reactive loopback are provided. In certain configurations, a front-end system includes an antenna port, a transmit port, a receive port, an antenna switch configured to selectively provide a transmit signal from the transmit port to the antenna port, a low noise amplifier having an input electrically connected to the antenna port and an output electrically connected to the receive port, and a loopback circuit including a reactive loopback impedance and a back switch electrically connected in series between the antenna switch and the receive port. The reactive loopback impedance includes a plurality of capacitors in series with the back switch and operable to provide a portion of the transmit signal to the receive port when the back switch is activated.