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A phase shift module is a microwave network module which provides a controllable phase shift of the RF signal. [ 1 ] [ 2 ] [ 3 ] Phase shifters are used in phased arrays . [ 4 ] [ 5 ] [ 6 ]
Alternatively, the phase shift of each symbol sent can be measured with respect to the phase of the previous symbol sent. Because the symbols are encoded in the difference in phase between successive samples, this is called differential phase-shift keying (DPSK). DPSK can be significantly simpler to implement than ordinary PSK, as it is a 'non ...
Amplitude and phase-shift keying (APSK) is a digital modulation scheme that conveys data by modulating both the amplitude and the phase of a carrier wave. In other words, it combines both amplitude-shift keying (ASK) and phase-shift keying (PSK).
Dynamic – an array of variable phase shifters are used to move the beam; Fixed – the beam position is stationary with respect to the array face and the whole antenna is moved; There are two further sub-categories that modify the kind of dynamic array or fixed array. Active – amplifiers or processors are in each phase shifter element
Binary phase-shift keying (BPSK) is used in the 868 and 915 MHz bands, and offset quadrature phase-shift keying (OQPSK) that transmits two bits per symbol is used in the 2.4 GHz band. The raw, over-the-air data rate is 250 kbit/s per channel in the 2.4 GHz band, 40 kbit/s per channel in the 915 MHz band, and 20 kbit/s in the 868 MHz band.
The input sinusoidal voltage is usually defined to have zero phase, meaning that it is arbitrarily chosen as a convenient time reference. So the phase difference is attributed to the current function, e.g. sin(2 π ft + φ), whose orthogonal components are sin(2 π ft) cos(φ) and sin(2 π ft + π /2) sin(φ), as we have seen.
Additionally, fine control of the beam direction can be provided with variable phase shifters in addition to the fixed phase shifters. [10] By using the variable phase shifters in combination with switching the power to the beam ports, a continuous sweep of the beam can be produced.
A waterfall display depicting several PSK31 transmissions at around 14.07 MHz. The green lines indicate a station that is transmitting. PSK31 or "Phase Shift Keying, 31 Baud", also BPSK31 and QPSK31, is a popular computer-sound card-generated radioteletype mode, used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat, most often using frequencies in the high ...