Patent ID: 7286080
Filing Date: 2007-10-23
Classification: G01S

Abstract:
1. A high-frequency transmitting/receiving apparatus comprising: a high-frequency oscillator for generating a high-frequency signal; a branching device connected to the high-frequency oscillator, for branching the high-frequency signal into high-frequency branch signals so that the high-frequency branch signals are outputted to one output end and another output end of the branching device, respectively; a modulator connected to the one output end of the branching device, for modulating the high-frequency branch signal branched to the one output end so as to output a high-frequency signal for transmission; a circulator formed of a magnetic substance, and having a first terminal, a second terminal, and a third terminal that are arranged about a periphery of the magnetic substance, of which the first terminal receives an output from the modulator, wherein a high-frequency signal inputted from one of the terminals is outputted from the other adjoining terminal in turn, in order from the first through third terminals; a transmitting/receiving antenna connected to the second terminal of the circulator; a mixer connected between the other output end of the branching device and the third terminal of the circulator, for mixing the high-frequency branch signal branched to the other output end and a high-frequency signal received by the transmitting/receiving antenna so as to generate an intermediate-frequency signal; and a switching device connected to an output end of the mixer, which interrupts the intermediate-frequency signal in an opened state, and, when the high-frequency signal for transmission from the modulator is in a non-output state and the condition is stabilized, changes from the opened state to a closed state to allow passage of the intermediate-frequency signal.