摘要:
An FSK radio receiver of direct conversion type, which derives baseband in-phase and phase quadrature signals from a received FSK RF signal in respective mixers by applying local oscillator signals to the mixers differing in phase by 90.degree., in which wide-band baseband 90.degree. phase shifting circuits formed of only digital logic elements phase shift the in-phase and phase quadrature signals to enable a demodulated digital data signal to be obtained by subsequent digital processing. In that processing, signals having a frequency that is double that of the in-phase and phase quadrature signals are derived and used to derive the demodulated data signal, ensuring high accuracy of detection and lowering the accuracy required for the local oscillator frequency.
摘要:
A data receiver includes first and second mixers mixing an input RF signal and a local oscillator signal and generating first and second quadrature baseband-frequency output signals. A phase shifter shifts a phase of the first baseband-frequency output signal by 90 degrees. A third mixer mixes an output signal from the phase shifter and the first baseband-frequency output signal. A fourth mixer mixes the first and second baseband-frequency output signals. A demodulator performs data demodulation by use of output signals from the third and fourth mixers.
摘要:
A high frequency oscillator comprising a ring type inductive resonator of a microstrip line constituted in a rectangular or annular loop. Capacitors are serially connected to both ends of the line, thereby improving the low-noise, separation and stability characteristics by use of the steep-phase characteristic of the ring-shaped resonator.
摘要:
A wide band analog frequency divider circuit operable at a high frequency in the GHz band. The analog frequency divider circuit comprises an LC series circuit having a capacitor and an inductor connected between the anode and the cathode of a diode, and means for applying a forward bias to the diode. The input signal is supplied from the anode side of the diode, and the output is delivered from the cathode side, or the anode side if the cathode is grounded.
摘要:
A frequency synthesizer for use in a high-frequency multichannel radio apparatus and so on. More particularly, a phase-locked loop (PLL) type frequency synthesizer which can perform a pulling process at high speed. Namely, a frequency synthesizer of the present invention can effect a pulling process at high speed by putting input signals to a phase comparator into a state in which the input signals are in phase with each other in an intermittent operation mode and can have strong resistance to noises by providing a 1-bit data latch and gate circuits in a data inputting portion thereof and synthesizing strobe signals at the time of inputting data thereto.
摘要:
A first oscillator outputs a signal having a reference frequency. A first frequency divider divides the frequency of the output signal from the first oscillator. A second oscillator outputs a signal having a target frequency. A second frequency divider divides the frequency of the output signal from the second oscillator. A phase comparator compares phases of output signals from the first and second frequency dividers. An integrator integrates an output signal from the phase comparator and controls the second oscillator in accordance with the integration of the output signal from the phase comparator. A first gate is connected between the first oscillator and the first frequency divider. A second gate is connected between the second oscillator and the second frequency divider. A third gate is connected between the phase comparator and the integrator. The first gate, the second gate, and the third gate are controlled in accordance with the output signals from the first and second frequency dividers and with an external synthesizer control signal.
摘要:
A resonator for microwave or VHF-UHF bands has a ring dielectric plate, one surface of which is metalized to make a resonant line, and at least one of other surfaces of which is also metalized to make a grounded or earth conductor. The resonator is very small in size and has a large unloaded Q value. Several embodiments are disclosed.
摘要:
A wide band analog frequency divider circuit operable at a high frequency in the GHz band, and a frequency synthesizer utilizing the analog frequency divider circuit. The analog frequency divider circuit comprises an LC series circuit having a capacitor and an inductor connected between the anode and the cathode of a diode, and means for applying a forward bias to the diode. The input signal is supplied from the anode side of the diode, and the output is delivered from the cathode side, or the anode side of the cathode is grounded. The frequency synthesizer is arranged to frequency divide the output of a VCO by the analog frequency divider circuit, and to supply the frequency-divided output to a prescaler. The output of the prescaler is further frequency divided by a programmable divider, and the phase difference between the output of the programmable divider and a reference signal is detected thereby to control the oscillation frequency of the VCO.
摘要:
A hemispherical dielectric resonator is arranged on a conductive substrate with a flat surface of the resonator in contact with the conductive substrate and fixed by a pair of fixing blocks. The dielectric resonator is fed with a signal feeder at a position at one side of the resonator such that intensity of the electric field is higher at that position. The fixing blocks contact a portion of the dielectric resonator where the intensity of the electric field is of a local minimum.
摘要:
A strip dual mode loop resonator includes loop-shaped strip line having a pair of straight strip lines arranged in parallel, an electric length of the loop-shaped strip line being equivalent to a wavelength of a microwave circulated in the loop-shaped strip line in two different directions according to a characteristic impedance of the loop-shaped strip line, and the straight strip lines being coupled to each other in electromagnetic coupling to change the characteristic impedance of the loop-shaped strip line. The microwave is transferred from an input strip line to the loop-shaped strip line through electromagnetic field induced by the microwave. Thereafter, the microwave is reflected in the straight strip lines of the loop-shaped strip line to produce reflected microwaves circulated in opposite directions. Thereafter, the reflected waves are resonated and filtered in dual mode in the loop-shaped strip line. Thereafter, the microwave formed of the reflected waves is transferred from the loop-shaped strip line to an output strip line through electromagnetic field induced by the microwave.