Patent ID: 8941536
Filing Date: 2015-01-27
Classification: G01S,H01P

Abstract:
1. A homodyne radar system, comprising: an oscillator configured to generate a transmit signal; an antenna configured to transmit the transmit signal and to receive a receive signal; a low noise amplifier configured to amplify the received signal to provide an amplified signal; a mixing subsystem configured to receive and mix the transmit signal and the amplified signal to produce an output signal; and a directional coupler coupled to the antenna, the oscillator, the low noise amplifier and the mixing subsystem, the directional coupler including a first transmission line, an input port at a first end of the first transmission line, a through port at a second end of the first transmission line, a second transmission line, a coupled port at a first end of the second transmission line, and an isolated port at a second end of the second transmission line, the first end of the first transmission line being proximate the first end of the second transmission line, and the second end of the first transmission line being proximate the second end of the second transmission line, wherein the antenna is coupled to the input port, the low noise amplifier is coupled to the through port, the oscillator is coupled to the coupled port, and mixing system is coupled to the isolated port, and wherein the directional coupler is configured to provide a low-loss transmission path from the antenna to the low noise amplifier and a high-loss transmission path from the oscillator to the antenna, the first transmission line providing the low-loss transmission line.