| 释义 |
up-conˈverter Chiefly Electr.
[up- 8.]
A device for converting a signal to a higher frequency. So up-conˈversion; also up-conˈvert v. trans., up-conˈverted ppl. a.
1958Bell Syst. Technical Jrnl. XXXVII. 989 (heading) Gain and noise figure of a variable-capacitance up⁓converter. Ibid., In up-conversion (modulation) a power gain results, with the power added to the input signal being supplied by the beat oscillator. In down⁓conversion a power loss results. 1968Microwave Jrnl. Aug. 52/2 The 12·4 GHz signal from the frequency up-converter is first down-converted to 160 MHz..then upconverted to 12·4 GHz in a single frequency parametric upconverter. 1970New Yorker 11 Apr. 34 A laser beam can be used to upconvert infrared light to visible light. 1972Physics Bull. Jan. 18/2 Since the upconverted radiation now has a wavelength close to both the helium–neon and krypton (0·605 µm) wavelengths, an accurate interferometric comparison is much easier to perform than with the 9·3 µm line directly. 1972Upconverter [see parametric a.1 b]. 1975D. G. Fink Electronics Engineers' Handbk. xiv. 72 There is a distinct advantage to up-conversion; image rejection is easily achievable by a simple low-pass filter. 1976Which? Nov. 262/3 UHF signals received at the aerial are sometimes translated to VHF or even lower frequencies (HF). These VHF (or HF) signals can't be plugged directly into a UHF TV... They need either a box (called an up-converter) to turn them back into UHF signals, or a specially modified TV. 1983E. Trundle Beginner's Guide Videocassette Recorders v. 91 The up-conversion process during replay involves a heterodyne system. |