| 释义 |
heterodyne, a. (and n.) Electr.|ˈhɛtərəʊdaɪn|
[f. hetero- + -dyne.]
Pertaining to, involving, or designating the production of a beat frequency by the combination of two oscillations of slightly different frequency, esp. as a method of radio detection in which one oscillation is the incoming signal and the other is produced in the receiver. Also (now rare) as n., a heterodyne receiver or its local oscillator.
1908J. Erskine-Murray tr. Ruhmer's Wireless Teleph. 201 One of the most interesting of Professor Fessenden's many inventions is what he has called the ‘Heterodyne’ receiver. 1915W. H. Eccles Wireless Telegr. 151 In receiving signals sent out by the spark sets..the heterodyne produced a telephone current variation averaging 4·65 times that due to the liquid barretter alone. 1919Wireless World Mar. 663 (heading) Heterodyne reception. 1922A. F. Collins Bk. Wireless Telegraph iii. ii. 174 The oscillations set up by the incoming waves from the distant sending stations and those set up by the separate oscillator tube, or heterodyne..have a slightly different frequency. 1931B.B.C. Yearbk. 442/2 Heterodyne interference, interference caused to broadcast reception by the carrier wave of an unwanted station beating with that of the wanted station. Ibid., Heterodyne reception, a method of receiving C.W. wireless signals in which use is made of a local oscillator to ‘beat’ with or ‘Heterodyne’ the incoming C.W. 1946Nature 6 July 33/1 The usual heterodyne methods of measuring a frequency..can be extended to the highest frequencies now in general use. 1957W. Fraser Telecommunications xxii. 735 The heterodyne waveform when rectified produces a current which varies in amplitude at the beat frequency.
fig.1930Musical Assoc. Proc. 97 To write atonally in a harmonic form at present is to produce a thought ‘heterodyne’.
Hence ˈheterodyne v. trans., (a) to produce heterodyne interference with (a radio station) (obs.); (b) to change the frequency of (a signal) by a heterodyne process; intr., to combine so as to produce beat oscillations or a different frequency; ˈheterodyning vbl. n. and ppl. a.; ˈheterodyned ppl. a.
1923Glasgow Herald 15 Oct. 6 A spark station previously heterodyned by a carrier. 1925Ibid. 10 Nov. 8 Glasgow can be as effectively ‘heterodyned’ by a German station as Radio Paris can be by a Spanish one working on an almost identical wave-length. 1926Encycl. Brit. III. 1044/2 If the signal current has a frequency of 105 cycles (3,000 metres), to give it an audible frequency of c{pp}-512 the heterodyning current must have a frequency of 105 plus or minus 512. 1933K. Henney Radio Engin. Handbk. x. 274 The frequencies in this selected range are made to heterodyne with an oscillator at a frequency of 42,000 cycles. 1934Proc. IRE XXII. 1269 The oscillator operated at a higher frequency than the incoming carriers and heterodyned them to 6 and 7 megacycles. 1943C. L. Boltz Basic Radio xiv. 223 This sound is called the heterodyne note, and the process is called heterodyning. 1965Wozencraft & Jacobs Princ. Communication Engin. vi. 493 At the receiver the signals are heterodyned back down from passband to baseband. 1967Electronics 6 Mar. 288/3 In this coherent conversion system, heterodyning converts incoming reference and test signals to 45 Mhz and then to 1 kilohertz. Ibid. 291/1 A comparison is made between the phase of a heterodyned 1-khz test signal and the phase of a second 1-khz signal. 1972Science 20 Oct. 252/2 It arises because the emission heterodynes with the collinear laser beam.
fig.1931T. H. Pear Voice & Personality iv. 44 The rudeness..heterodynes the shyness. So, while an unselective receiver, or strange listener, perceives a jumbled mixture of both, the ear which is sensitised to rudeness hears it only, while you hear only shyness. |