摘要:
The present invention provides a structure for attaching an RFID tag in a disposition allowing an easy detection by an external RFID reader, the structure preventing the RFID tag from being broken for a normal specification, and a method for detecting an RFID tag. The structure for attaching an RFID tag to a hollow cylindrical metal body is characterized in that the RFID tag is attached to an inner side of the hollow cylindrical metal body via a spacer between it and a metal surface such that a direction in which an electric field of the RFID tag is generated is in a direction along a circumference of the hollow cylindrical metal body.
摘要:
Existing modems of time division duplex (TDD) type can be utilized without modification to perform a high speed wireless communication with stable communication quality in other frequency bands such as quasi-millimeter to millimeter wave bands. There are included a circulator (11) connected to TDD modems (1, 2) and receives signals transmitted thereby to output those signals from a first connection terminal (p1) and outputs signals received at a second connection terminal (p2) to the TDD modems (1, 2), and a frequency converter (2a) that raise the frequency of the signals from the circulator (11) by a predetermined frequency width and lowers the frequency of signals from a receive antenna (32) by a predetermined frequency width. It may be arranged that the frequency conversion width be made different between the uplink and downlink and that a filter, which blocks the transmitting wireless frequency and passes the receiving wireless frequency, is provided between the receive antenna (32) and a frequency converter (22a).
摘要:
A phase and frequency detector circuit includes both a phase comparator such as an exclusive-OR gate possessing high phase sensitivity, and a frequency-phase comparator that is sensitive to differences in frequency. The outputs of these circuits are combined to provide a single output signal offering both frequency discrimination and sharp phase discrimination.
摘要:
An oscillator includes phase frequency detectors, each detecting the phase difference between two input signals (output signal and external reference signal) and outputting a control command signal for controlling the output signal to achieve a desired frequency on the basis of the phase difference. A plurality of ICs, each including a phase frequency detector, frequency dividers, a charge pump, and a lock detection circuit, is operated in parallel. A composite control command signal generated by combining outputs of the phase frequency detectors is output via a loop filter to a voltage-controlled oscillator. Whether phase noise is reduced sufficiently is determined on the basis of detection results by an amplitude detection circuit for detecting the amplitude of an AC component of the composite control command signal and the lock detection circuits. The phase frequency detectors are repeatedly reactivated until the phase noise is reduced sufficiently.
摘要:
The present invention provides a negative resistance input amplifier including: a microstrip line having one end connected to a collector of a transistor and the other end being open with a length of ¼ of a wavelength λ at a predetermined frequency f; and a microstrip line having one end connected to an emitter of the transistor and the other end grounded with a length of ¼ of the wavelength λ at the predetermined frequency f so that impedance viewed from a base of the transistor becomes negative only at around a target frequency, and an oscillator using the negative resistance input amplifier.
摘要:
An oscillator according to the present invention includes: an active element that oscillates at a predetermined frequency to output a signal of the predetermined frequency; and an impedance element having an impedance that is lower at a frequency lower than the predetermined frequency than at the predetermined frequency, the active element having signal terminals at least one of which is grounded through a series circuit composed of the impedance element and a capacitor.
摘要:
An oscillator includes phase frequency detectors, each detecting the phase difference between two input signals (output signal and external reference signal) and outputting a control command signal for controlling the output signal to achieve a desired frequency on the basis of the phase difference. A plurality of ICs, each including a phase frequency detector, frequency dividers, a charge pump, and a lock detection circuit, is operated in parallel. A composite control command signal generated by combining outputs of the phase frequency detectors is output via a loop filter to a voltage-controlled oscillator. Whether phase noise is reduced sufficiently is determined on the basis of detection results by an amplitude detection circuit for detecting the amplitude of an AC component of the composite control command signal and the lock detection circuits. The phase frequency detectors are repeatedly reactivated until the phase noise is reduced sufficiently.
摘要:
In a frequency converter, a phase-locked loop generates a local-oscillation signal having a low frequency, of a plurality of local-oscillation signals having different frequencies, based on an intermediate frequency beacon signal that results from mixing a predetermined beacon signal with the local-oscillation frequency signal. Even if the phase-locked loop is used to generate the low frequency local-oscillation signal only, a frequency offset and a phase noise taking place in remaining high frequency local-oscillation signals are compensated for or canceled out. The frequency converter thus results in a high frequency accuracy. This arrangement reduces the number of bulky, costly and power-consuming phase-locked oscillators, typically used in the quasi millimeter band or the millimeter band. A simplified, compact frequency converter is thus provided, reducing both installation and operating costs.
摘要:
An oscillator includes phase frequency detectors, each detecting the phase difference between two input signals (output signal and external reference signal) and outputting a control command signal for controlling the output signal to achieve a desired frequency on the basis of the phase difference. A plurality of ICs, each including a phase frequency detector, frequency dividers, a charge pump, and a lock detection circuit, is operated in parallel. A composite control command signal generated by combining outputs of the phase frequency detectors is output via a loop filter to a voltage-controlled oscillator. Whether phase noise is reduced sufficiently is determined on the basis of detection results by an amplitude detection circuit for detecting the amplitude of an AC component of the composite control command signal and the lock detection circuits. The phase frequency detectors are repeatedly reactivated until the phase noise is reduced sufficiently.
摘要:
In a frequency converter, a phase-locked loop generates a local-oscillation signal having a low frequency, of a plurality of local-oscillation signals having different frequencies, based on an intermediate frequency beacon signal that results from mixing a predetermined beacon signal with the local-oscillation frequency signal. Even if the phase-locked loop is used to generate the low frequency local-oscillation signal only, a frequency offset and a phase noise taking place in remaining high frequency local-oscillation signals are compensated for or canceled out. The frequency converter thus results in a high frequency accuracy. This arrangement reduces the number of bulky, costly and power-consuming phase-locked oscillators, typically used in the quasi millimeter band or the millimeter band. A simplified, compact frequency converter is thus provided, reducing both installation and operating costs.