In order to save the number of antennas, modern RF systems basically use transceiver shared antenna, so it is inevitable to involve a duplexer. antenna diplexer is a signal switching device used by radio measuring equipment when a transmitter and receiver share an antenna. A diplexer is a device with two operating states.
Superficially, the diplexer is a three-port device designed to solve the problem of transmitting and receiving the same antenna without their mutual influence.
An antenna feeder with both uplink and downlink functions.
Uplink frequency of 27.5-31.0 GHz; Downlink frequency of 17.7-21.2 GHz .
It realizes the isolation of the transmitted signal and the received signal, ensuring that the transmitted signal is transmitted only to the antenna, so that the received signal is transmitted only to the receiver. Radar antenna receiver and transmitter switch is a kind of antenna diplexer.
(1) TDD, Time Division Diplexing
Time division diplexer, mainly transmitting and receiving in time separate, do not conflict with each other. Like transmitting and then receiving. This type of diplexer is used in radar (radar says: it is determined by my work personality: first to transmit the signal, then to receive the reflected signal). Generally composed of ring or light diplexer;
(2) TDD, Frequency Division Diplexing
Frequency division diplexer, mainly because of the different working frequency bands of the transceiver link. The main function of the diplexer is to isolate the transmission and reception signals of different frequencies from each other, so as to ensure that both transmission and reception can work normally at the same time. It can be composed of two sets of stop-band filters with different frequencies to prevent the transmission signal from the machine from being transmitted to the receiver. Orthogonal mode couplers (OMTs) can also be used to separate or synthesize two different orthogonally polarized waves.
A multiplexer is usually a combination device for transmitting/receiving multiple frequency channels.
When electromagnetic waves propagate from medium A to medium B, due to the differences in the media, a portion of the electromagnetic energy will be reflected, leading to the formation of standing waves in region A. The voltage peak-to-peak to voltage trough ratio of these standing waves is known as the Voltage Standing Wave Ratio (VSWR). An ideal VSWR is 1:1, while the worst VSWR is infinite, indicating no energy transmission and full reflection.
Gain: The gain is the ratio of the signal power density produced by the actual antenna and the ideal antenna at the same point in space, under the same input power conditions, due to the addition of oscillators. The magnitude of gain reflects the concentration of energy radiated by the antenna, with larger dB values indicating greater energy concentration.
