Patent ID: 7714777

Claim:
A semiconductor device for a spread spectrum radar apparatus, the semiconductor device being embedded in the spread spectrum radar apparatus which transmits, as a detection radio wave, a broad-band signal generated using a pseudo-noise code, receives a reflected wave of the detection radio wave that is reflected at an object and returns, and detects the object by the reflected wave of the detection radio wave using the pseudo-noise code, said semiconductor device comprising: an unbalanced to balanced transforming circuit which includes a first coupled line and a second coupled line that receive, as an unbalanced signal, a received signal corresponding to the reflected wave of the detection radio wave, and which converts the received signal into a pair of a balanced signal consisting of a positive signal and a negative signal, and outputs the pair of the balanced signal from said first coupled line and said second coupled line; and a balanced inverse spread spectrum circuit which includes a switch circuit having at least one transistor, and which receives, as a differential signal, pseudo-noise codes belonging to a same sequence code as the pseudo-noise code which is used in the generation of the broad-band signal, obtains the pair of the balanced signal from said unbalanced to balanced transforming circuit, performs inverse spread spectrum modulation on the pair of the balanced signal to generate a differential signal by said switch circuit using the pseudo-noise codes as the differential signal, and outputs, as output signals, the differential signal generated by the inverse spread-spectrum modulation, wherein said unbalanced to balanced transforming circuit and said balanced inverse spread spectrum circuit are formed on a same semiconductor substrate.