公开(公告)号：US3891926A

公开(公告)日：1975-06-24

申请号：US31581872

申请日：1972-12-18

申请人： AMERICAN STANDARD INC

发明人： ISHMAN NEAL H ,  LENERT RICHARD W ,  GOLDMAN JEFFREY B

IPC分类号： H04B1/40 ,  H04B1/04

CPC分类号： H04B1/405

摘要： A radio transceiver, capable of transmitting and receiving in any of a large number (7000.) of channels over a band of frequencies almost an octave wide in the u.h.f. spectrum, which includes a tunable frequency synthesizer operable over the band 225-400 MHz., in 25 KHz. channel spacings, a driver amplifier responsive to the synthesizer over the entire band, a filter of the multi-cavity resonator type continuously tunable over the band and a broad band power amplifier responsive to the output of the filter, amplitude modulation of carrier derived from the power amplifier being achieved at the driver amplifier in response to an error signal equal to the difference between a rectified version of the output of the power amplifier and an audio input signal. Since the cavity resonator presents a load to the driver amplifier which looks like a short circuit when the filter is not correctly tuned, the driver output stages, operating Class C, are bypassed during tuning, drive during tuning being achieved from Class A drivers of the Class C stages until the filter is completely tuned, and in the latter process rough tuning being achieved in terms of a comparison of power reflected from the input of the filter and issuing out of the filter, and fine tuning being achieved in response to phase comparison of the signals at the input and issuing out of the filter. The filter is tuned by a reversible drive motor, which runs the filter through its range. Reflected and output signal amplitudes at the filter are compared to derive a maximum output amplitude signal, which renders logic circuitry responsive to measurements of phase difference between input and output signals. Phase differences achieve plural zeros in passing into and out of the resonance frequency of the filter and logic circuitry is provided which causes repeated reversals of the motor, with progressively descreasing speed, in response to phase differences, as tuning passes from one side to the other of a true zero, until the motor comes to rest.

摘要翻译： 一种无线电收发器，能够在u.h.f中的频率几乎为八度宽的频带中以大量（7000.）的信道中的任何一个发送和接收。 频谱，其包括可在25KHz范围内在225-400MHz频带上操作的可调谐频率合成器。 通道间隔，在整个频带上响应于合成器的驱动放大器，可在频带上连续调谐的多空腔谐振器型滤波器和响应于滤波器输出的宽带功率放大器，来自 响应于等于功率放大器的输出的整流版本与音频输入信号之间的差的误差信号，在驱动器放大器处实现功率放大器。 由于空腔谐振器对滤波器未正确调谐时看起来像短路的驱动放大器提供负载，所以在调谐期间绕过驱动器输出级C，在调谐期间驱动调谐期间从A类驱动器 C级阶段，直到滤波器完全调谐，并且在后一过程中，从滤波器的输入和从滤波器的输出反射的功率的比较来实现粗调，并且响应于相位比较而实现微调 的输入信号并发出滤波器。