heterodyne


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heterodyne

produced by, operating by, or involved in heterodyning two signals

Heterodyne

 

a low-power tube-type or semiconductor generator of electrical oscillations used for frequency conversion in superheterodyne radio receivers, wavemeters, and other devices. The heterodyne generates oscillations of the subcarrier frequency, which are mixed with incoming high-frequency oscillations, resulting in the formation of a constant difference frequency (intermediate frequency). The heterodyne must possess a high stability of frequency and insignificant harmonic oscillation amplitudes. A frequency-tunable laser may serve as the heterodyne in optical-frequency receivers.

heterodyne

[′hed·ə·rə‚dīn]
(electronics)
To mix two alternating-current signals of different frequencies in a nonlinear device for the purpose of producing two new frequencies, the sum of and difference between the two original frequencies.

heterodyne

The mixing of two electrical or acoustic signals to produce a third equal to either the sum of or the difference between their frequencies. For example, if a signal with a frequency of 1000 Hz were to be mixed with another signal of 600 Hz, besides the original two frequencies two new frequencies will be produced: 1600 Hz (1000 + 600), and 400 Hz (1000—600). Radar receivers are of the heterodyne type (as contrasted to the superregenerative type) because the very high radio frequencies used in radar are difficult to amplify. A target signal is heterodyned with a current of lower frequency produced by a klystron oscillator and the resulting intermediate-frequency signal can then be highly amplified for subsequent presentation or analysis.

heterodyning

Using an electronic circuit to combine an input radio frequency with one that is generated in order to produce new frequencies: one that is the sum of the two and another that is the difference of the two. Heterodyning is typically used to bandshift incoming frequencies into intermediate frequencies for demodulation. For heterodyning examples, see superheterodyne receiver.
References in periodicals archive ?
Schnecker explained further, "Optical coherent receivers use an LO laser to generate a low IF because it is impractical to build an optical phase-locked loop (PLL) that would allow full heterodyne mixing as is done in RF applications.
PRINCIPLE OF HETERODYNE UP-CONVERSION AND DOWN-CONVERSION
Therefore, the modules comprise complete heterodyne receivers, performing frequency downconversion, filtering and amplifying to a power level commensurate with the A/D converter, as shown in Figure 2.
All the circuits developed are integrated circuits for heterodyne or superheterodyne receivers.
In addition, it was a year in which direct-conversion architectures, using RF CMOS, gained legitim acy and a year where Bi-CMOS and super heterodyne designs had their supporters as well."
Direct conversion, low-IF and heterodyne systems will be evaluated for the receiver and judged on which implementation is suited for different combinations of standards.
The proposed heterodyne transceiver architecture for an 802.11a WLAN application (5.725 to 5.825 GHz) is shown in Figure 2.