Abstract: Two lines Ai1 (i=1 or 2) are connected to an input terminal In. The line Ai1 is grounded via a capacitor Ci1. The line Ai1 and a line Bi1 form a coupled line. One end of the line Bi1 is connected to a positive pole of a diode Di1 which is grounded at its negative pole. Lines Bi0 and Bi2 are connected to the other end of the line Bi1. The other end of the line Bi0 is connected to a capacitor Ci0 which is grounded at its other end and a resistor Ri0 which is connected to a voltage control terminal VCTLi at its other end. The other end of the line Bi2 is connected to the positive pole of a diode Di2. The line Bi2 and the line Ai2 form a coupled line. One end of the line Ai2 is connected to an output terminal Out-i, and the other end is grounded via a capacitor Ci2. The output of the terminals Out-1, 2 are switched to 5.8 GHz band, 4.8 GHz band and cut-off, by applying to VCTL1 and VCTL2 three potentials, that is, ground potential.

Abstract: A start signal outputting circuit according to the invention has a differential RF/DC convertor part 100 for converting a high frequency power (RF) into a d.c. potential (DC). The RF/DC convertor part 100 is formed by two transistors QRD, QDD working as a diode, and transistors QR1˜R3, QD1˜D3 and resistances RR1˜R3 for forming high resistances at anode sides and cathode sides of these diodes, respectively. A differential amplification part 200 disposed at a later stage of the diode has not only amplifying effect but also low-pass filtering effect together with filtering pars 120, 210 of its previous and later stages. In this case, it is designed so that current flowing through the respective circuits is about 2˜3 ?A. As a result, even if the high frequency power of the specified frequency is weak, for example ?60˜?40 dBm, a start signal outputting circuit 1000 which outputs a d.c. potential of 0.3˜2.4V, is suitable for integration and has a low power consumption can be obtained.

Abstract: A start signal output circuit having an RF/DC conversion circuit to which radio frequency power (RF) of specified frequency is inputted and from which a direct current potential (DC) is outputted, comprises a detection/amplification circuit 210 which includes a voltage doubler wave-detector circuit 10 configured including a sensing diode Q1 (Tr34) for sensing the RF power, a differential amplifier including differential pair transistors Tr31 and Tr32, and a current mirror circuit. A base current of one Tr31 of the differential pair transistors is brought into substantial agreement with a DC component of a current flowing through the sensing diode Q1 (Tr34). A total of currents flowing through the differential pair transistors Tr31 and Tr32 is regulated to a substantially constant value by the current mirror circuit. Thus, the start signal output circuit which is small in size, high in sensitivity and low in power consumption can be realized.

Abstract: Two lines Ai1 (i=1 or 2) are connected to an input terminal In. The line Ai1 is grounded via a capacitor Ci1. The line Ai1 and a line Bi1 form a coupled line. One end of the line Bi1 is connected to a positive pole of a diode Di1 which is grounded at its negative pole. Lines Bi0 and Bi2 are connected to the other end of the line Bi1. The other end of the line Bi0 is connected to a capacitor Ci0 which is grounded at its other end and a resistor Ri0 which is connected to a voltage control terminal VCTLi at its other end. The other end of the line Bi2 is connected to the positive pole of a diode Di2. The line Bi2 and the line Ai2 form a coupled line. One end of the line Ai2 is connected to an output terminal Out-i, and the other end is grounded via a capacitor Ci2. The output of the terminals Out-1, 2 are switched to 5.8 GHz band, 4.8 GHz band and cut-off, by applying to VCTL1 and VCTL2 three potentials, that is, ground potential.

Abstract: A start signal outputting circuit according to the invention has a differential RF/DC convertor part 100 for converting a high frequency power (RF) into a d.c. potential (DC). The RF/DC convertor part 100 is formed by two transistors QRD,QDD working as a diode, and transistors QR1˜R3,QD1˜D3 and resistances RR1˜R3 for forming high resistances at anode sides andcathodesidesofthesediodes, respectively. Adifferential amplification part 200 disposed at a later stage of the diode has not only amplifying effect but also low-pass filtering effect together with filtering pars 120, 210 of its previous and later stages. In this case, it is designed so that current flowing through the respective circuits is about 2˜3 ?A. As a result, even if the high frequency power of the specified frequency is weak, for example ?60˜?40 dBm, a start signal outputting circuit 1000 which outputs a d.c. potential of 0.3˜2.4V, is suitable for integration and has a low power consumption can be obtained.

Abstract: A start signal output circuit having an RF/DC conversion circuit to which radio frequency power (RF) of specified frequency is inputted and from which a direct current potential (DC) is outputted, comprises a detection/amplification circuit 210 which includes a voltage doubler wave-detector circuit 10 configured including a sensing diode Q1 (Tr34) for sensing the RF power, a differential amplifier including differential pair transistors Tr31 and Tr32, and a current mirror circuit. A base current of one Tr31 of the differential pair transistors is brought into substantial agreement with a DC component of a current flowing through the sensing diode Q1 (Tr34). A total of currents flowing through the differential pair transistors Tr31 and Tr32 is regulated to a substantially constant value by the current mirror circuit. Thus, the start signal output circuit which is small in size, high in sensitivity and low in power consumption can be realized.