Abstract: This disclosure provides a radar apparatus, which includes an antenna for discharging a transmission beam with frequencies corresponding to elevation/depression angles with respect to a particular surface and receiving a reflection echo from a reflective body and a reception module for detecting an elevation/depression angle of the reflective body based on a frequency component of a reception signal received by the antenna and detecting a distance of the reflective body based on a time component of the reception signal.

Abstract: This disclosure provides a radar apparatus, which includes an antenna for discharging a transmission beam with frequencies corresponding to elevation/depression angles with respect to a particular surface and receiving a reflection echo from a reflective body and a reception module for detecting an elevation/depression angle of the reflective body based on a frequency component of a reception signal received by the antenna and detecting a distance of the reflective body based on a time component of the reception signal.

Abstract: A signal conversion apparatus includes a local oscillator for locally generating a signal having a frequency, a phase shifter for shifting the phase of the locally generated signal output from the local oscillator by an amount determined based on a relationship between the amount of phase shift and the amount of frequency pulling, and a converter for converting an input signal by using the phase-shifted locally generated signal output from the phase shifter. The phase shifter varies impedance between the local oscillator and the converter so that the oscillating frequency of the locally generated signal output from the local oscillator remains unchanged.

Abstract: There is provided a distortion compensation circuit that can compensate for the nonlinearity of an amplifier having the characteristic that the gain is reduced and the phase is delayed with an increase in input power. An inductor 112 is connected in series with a diode 105 of a distortion compensation circuit 100. The resistance components of the diode 105 decrease with an increase in input power, so that the effect of the impedance of the inductor 112 connected in series with the diode 105 appears, and the impedance of the distortion compensation circuit 100 becomes inductive, producing the characteristic that the phase is advanced. At the same time, the resistance components of the diode 105 decrease with an increase in input power, thus producing the characteristic that the loss is reduced and the gain is increased.

Abstract: There is provided a distortion compensation circuit that can compensate for the nonlinearity of an amplifier having the characteristic that the gain is reduced and the phase is delayed with an increase in input power. An inductor 112 is connected in series with a diode 105 of a distortion compensation circuit 100. The resistance components of the diode 105 decrease with an increase in input power, so that the effect of the impedance of the inductor 112 connected in series with the diode 105 appears, and the impedance of the distortion compensation circuit 100 becomes inductive, producing the characteristic that the phase is advanced. At the same time, the resistance components of the diode 105 decrease with an increase in input power, thus producing the characteristic that the loss is reduced and the gain is increased.

Abstract: A radar includes a transmitter circuit, a receiver circuit, an antenna and a circulator. The receiver circuit includes a low-noise amplifier which amplifies a received signal fed from the antenna through the circulator. A local oscillator provided in the receiver circuit generates a local oscillator signal of which frequency is approximately half the frequency of the received signal, and the local oscillator signal is amplified by a buffer amplifier. An even harmonic mixer including an anti-parallel diode pair also provided in the receiver circuit as a frequency converter mixes the received signal output from the low-noise amplifier with the local oscillator signal output from the buffer amplifier to generate and output an intermediate frequency signal.

Abstract: A signal conversion apparatus includes a local oscillator for locally generating a signal having a frequency, a phase shifter for shifting the phase of the locally generated signal output from the local oscillator by an amount determined based on a relationship between the amount of phase shift and the amount of frequency pulling, and a converter for converting an input signal by using the phase-shifted locally generated signal output from the phase shifter. The phase shifter varies impedance between the local oscillator and the converter so that the oscillating frequency of the locally generated signal output from the local oscillator remains unchanged.

Abstract: A radar includes a transmitter circuit, a receiver circuit, an antenna and a circulator. The receiver circuit includes a low-noise amplifier which amplifies a received signal fed from the antenna through the circulator. A local oscillator provided in the receiver circuit generates a local oscillator signal of which frequency is approximately half the frequency of the received signal, and the local oscillator signal is amplified by a buffer amplifier. An even harmonic mixer including an anti-parallel diode pair also provided in the receiver circuit as a frequency converter mixes the received signal output from the low-noise amplifier with the local oscillator signal output from the buffer amplifier to generate and output an intermediate frequency signal.

Abstract: A microwave/millimeter-wave integrated circuit realizes stable oscillation by reducing time-base variation in load impedance. This IC connects an oscillator to the input terminal of a lange coupler, and connects to the isolation port of the lange coupler a terminating resistor with resistance equal to the load impedance connected to the output terminals of the lange coupler. This stabilizes load impedance to the oscillator, and reduces variation in the oscillation frequency as a result of changes in load impedance.

Abstract: A microwave/millimeter-wave integrated circuit (IC) realizes stable oscillation by reducing time-based variation of a load impedance. This IC connects an oscillator to an input terminal of a Lange coupler and connects to the isolation port of the Lange coupler a terminating resistor having a resistance equal to the load impedance connected to the output terminals of the Lange coupler. This connection stabilizes load impedance to the oscillator, and reduces variation in the oscillation frequency as a result of changes in load impedance.

Abstract: A microwave and millimeter wave circuit includes an amplifier having an amplification center frequency, input and output terminals, and a source-grounded transistor. First and second transmission lines are connected between the input terminal and a gate of the transistor, and are connected in series to each other. Third and fourth transmission lines are connected between a drain of the transistor and the output terminal, and are connected in series to each other. A first band elimination filter is connected to the input terminal, and has a first stopping frequency, and a second band elmination filter is connected to the output terminal, and has a second stopping frequency. A third band elimination filter is connected to a connecting point between the first and second transmission lines and has a third stopping frequency, and a fourth band elimination filter is connected to a connecting point between the third and fourth transmission lines and has a fourth stopping frequency.

Abstract: A semiconductor device includes a semiconductor substrate on which are successively disposed, a semiconductor laminated layer structure including at least two semiconductor layers, a first semiconductor layer containing a first dopant impurity providing a first conductivity type, and a second semiconductor layer containing the first dopant impurity in a concentration higher than in the first semiconductor layer. A semiconductor diode includes a first electrode in ohmic contact with the second semiconductor layer, and a second electrode in Schottky contact with the second semiconductor layers. A transistor includes a gate electrode in the recess and making a Schottky contact with the first semiconductor layer, and a source electrode and a drain electrode disposed on opposite sides of the recess on the second semiconductor layer, and in ohmic contact with the second semiconductor layer.

Abstract: An impedance matching circuit employed at a high frequency includes a coupling line having a length longer than 1/4 of a wavelength at a design center frequency. Therefore, the impedance can be inductive and it is possible to impedance match a circuit comprising a transistor and having a capacitive impedance. The impedance matching circuit according to the present invention functions both as a dc blocking capacitor and an impedance matching circuit. Therefore, the degree of freedom in the circuit design is increased and the circuit can be reduced in size.

Abstract: A microwave switch circuit includes a first impedance conversion circuit, one end of which is connected to an input terminal; a resonance circuit connected between an output of the first impedance conversion circuit and ground and including a parallel connection of a field effect transistor and a resonance inductor; and a second impedance conversion circuit connected between the output of the first impedance conversion circuit and an output terminal. One microwave switch circuit may be connected between an antenna terminal and a signal input terminal and another microwave switch circuit may be connected between the antenna terminal and a signal receiving terminal. The microwave switch circuit output terminal and input terminal may have an impedance of 50 .OMEGA. and the output of the first impedance conversion circuit may have an impedance lower than 50 .OMEGA.. The microwave switch circuit may include one-fourth wavelength transmission lines as the first and second impedance conversion circuits.

Abstract: According to a method for producing semiconductor chips, grooves serving as dicing lines are formed in a front surface of a semiconductor wafer, the semiconductor wafer is ground from the rear surface to a prescribed thickness, leaving portions of the wafer opposite the grooves, a feeding layer is formed on the ground rear surface of the wafer, a metal layer for heat radiation is formed on the feeding layer, a dicing tape is applied to the metal layer, and the wafer and the feeding layer are diced along the dicing lines, resulting in a plurality of semiconductor chips. Therefore, the strength of the wafer is increased because portions of the wafer remain at the dicing lines, preventing curvature of the wafer.

Abstract: A microwave integrated circuit includes a matching circuits. The microwave integrated circuit includes a main transmission line having a strip line and a shorted stub or an open stub, all of which are arranged on a semiconductor substrate. A phase control circuit connected in parallel with the main transmission line controls the passing phase of the main transmission line. Therefore, the electrical length of the main line can be changed and the passing phase through the main line can be controlled for adjusting impedance matching in accordance with changes in the impedance of the element to be matched, resulting in precise impedance matching at a desired frequency.