Abstract: A compact millimeter wave radar transceiver at low cost is provided wherein a direct current voltage applying circuit is coupled to a high frequency line to apply a fast pulse wave without losing a sharp input pulse pattern. A voltage is applied to a negative resistance diode, such as a Gunn diode, which is variably controlled to vary the diode oscillating frequency signal, which signal is outputted as a transmitting wave. The transmitted wave is reflected by a target and received by the negative resistance diode. The received wave is detected as a heterodyne detection utilizing a non-linear property of the negative resistance diode. A frequency difference between the transmitted wave and the received reflected wave is outputted via a low-pass filter and processed to detect the target.

Abstract: A high-frequency circuit board free from variations in transmission impedance and having the desired characteristics is produced. A surface of a resin substrate is activated to form a roughened surface, and a thin-wall pattern of an electrically conductive metal is formed directly on the roughened surface of the resin substrate.

Abstract: A compact millimeter wave radar transceiver at low cost is provided wherein a direct current voltage applying circuit is coupled to a high frequency line to apply a fast pulse wave without losing a sharp input pulse pattern. A voltage is applied to a negative resistance diode, such as a Gunn diode, which is variably controlled to vary the diode oscillating frequency signal, which signal is outputted as a transmitting wave. The transmitted wave is reflected by a target and received by the negative resistance diode. The received wave is detected as a heterodyne detection utilizing a non-linear property of the negative resistance diode. A frequency difference between the transmitted wave and the received reflected wave is outputted via a low-pass filter and processed to detect the target.

Abstract: A high-frequency circuit board free from variations in transmission impedance and having the desired characteristics is produced. A surface of a resin substrate is activated to form a roughened surface, and a thin-wall pattern of an electrically conductive metal is formed directly on the roughened surface of the resin substrate.

Abstract: A variable phase shifter is improved in liquid crystal response characteristics by using a thin liquid crystal material as a dielectric substrate. The variable phase shifter includes two substrates disposed parallel to each other. The substrates have alignment layers on their mutually opposing inner surfaces. A liquid crystal layer is sealed in the area between the substrates. A transmission line is formed to meander on the inner surface of one of the substrates. A grounding conductor is formed on the inner surface of the substrate along the transmission line at a predetermined distance therefrom. External electrodes are formed at least in regions on the respective outer surfaces of the substrates, each of which regions corresponds to the gap between the transmission line and the grounding conductor. A bias voltage source applies a bias voltage between the upper and lower external electrodes.