JPH01124706U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one embodiment of the quadrature detection circuit of the present invention, and FIG. 2 is a circuit diagram showing another embodiment of the quadrature detection circuit of the present invention.
FIG. 3 is a circuit diagram showing another embodiment of the quadrature detection circuit of the present invention, and FIG. 4 is a diagram showing an example of a conventional quadrature detection circuit. 1: Antenna, 2: Front end, 3: Limiter circuit, 4: Phase shift circuit, 5: Multiplier circuit, 6, 6
': Differential amplifier, 7: Quadrature detection circuit,
8, 9: current mirror circuit, 10, 11: output terminal, 12: ground terminal, 13: power supply terminal, 14: level shift circuit.

Claims (1)

[Claims for Utility Model Registration] (1) A phase shifting circuit that shifts the phase of a limiter output, and a first differential amplifier that derives a constant current limiter output consisting of a positive phase and an inverted phase of the limiter output. , a limiter output whose phase has been shifted by 90 degrees by the phase shift circuit, and a second and third differential amplifier, into which the constant current limiter output consisting of the positive phase and inverted phase from the first differential amplifier is input. A quadrature detection circuit comprising a multiplication circuit consisting of an amplifier. (2) A phase shifting circuit that shifts the phase of the limiter output, a differential pair of transistors connected to a constant current source circuit, and a first and second load circuit connected to the collectors of the differential pair transistors, respectively. 1 differential amplifier circuit, a limiter signal whose phase is shifted by 90 degrees by the phase shift circuit, and a constant current limiter output consisting of a positive phase and an inverted phase from the first differential amplifier. 2 and a multiplication circuit consisting of a third differential amplifier, wherein the first and second load circuits calculate the difference between the second and third differential amplifiers. A quadrature detection circuit characterized in that a limiter circuit and the multiplication circuit are combined by forming first and second current mirror circuits together with transistors connected in a dynamic pair. (3) The first and second level shift circuits, which consist of first and second transistors to which positive-phase and inverted-phase limiter outputs are supplied, respectively, and a current source circuit connected to the emitters of these transistors, are configured as a quadrature. A first circuit provided before the detection circuit and configured to receive the limiter outputs obtained from the first and second level shift circuits and derive a constant current limiter output.
a differential amplifier, a phase shift circuit that shifts the phase of the limiter output obtained through the level shift circuit, and a limiter output whose phase is shifted by 90 degrees from the phase shift circuit and a positive phase output from the first differential amplifier. 1. A quadrature detection circuit comprising a multiplication circuit comprising second and third differential amplifiers to which a constant current limiter output having an inverted phase and a constant current are input. (4) The first differential amplifier circuit includes a constant current source circuit, first to fourth transistors whose emitters are commonly connected and connected to the constant current source circuit, and the first and third transistors. a first and a third diode connected to respective collectors of the transistor;
The quadrature detection according to claims 1, 2 and 3, wherein the diode forms a current mirror circuit together with a fifth transistor, and the output stage transistor of the current mirror circuit is connected to a phase shift circuit. circuit.