In the field of radio technology and telecommunications, two basic passive component RF components, couplers and power distributors are used, which are used to split / combine or split electromagnetic signals. Although they are devices of the same class, there are some major differences in the way the signals are split / split as well as the actual roles.
A power divider and a coupler are passive devices, because they do not have an energy source for the signal that passes the signal. A power divider is a term that is often used interchangeably with a power divider. In fact, the two devices are separate components and have different characteristics.
The similarity lies in the fact that it splits / splits power with two separate lines. These devices are differentiated to physical characteristics and applications.
A Power splitter It is a unidirectional passive device that can not be used as a power combination device. It has a higher input port than the two output ports. This makes it possible to use it as a calibration and leveling device.
A Power distributor (Bidirectional), and all ports (one input port and two output ports) have the same resistance value. This allows the device to split one signal on two lines, as well as split the two signals into one transmission line.
A Directional coupler Is a passive device with 4 different ports. It has an input port, a transmission port, a couple port, and a separation port. The device makes it possible to separate one incoming signal through the input port with two signals of different amplitudes (on two coupled lines).
The main line has a larger output, the coupling line is smaller, and the difference can be calculated by "coupling coefficient". There are several applications for this device, which can be used with amplifiers, receivers, transmitters and measuring devices.
A special case of a directional coupler is a hybrid coupler (3 dB directional coupler). This coupler divides the power equally. The phase difference of the output determines which type of hybrid coupler is on hand: 90 degree hybrid or 180 degree hybrid. These special couplers are important for devices such as mixers, power combiners, dividers, modulators, and some radar antennas.
The difference between the coupler and the power divider is as follows.
• The power divider has three ports and is used to split the signal into two parts with equal power splitting the equal amplitude and phase balance of the signal between the two output ports. The directional coupler has four ports and provides absolute division other than the hybrid coupler. It splits the power so that what comes through the first port is split into parts through port 2 (binding port) while the remaining power is supplied through the third port. The fourth port is isolated and the power supply (at least ideally) will not be sent.
• The 4-port coupler does not use internal resistance but has a single "terminated" isolation port. Instead, the 3-door divider has no internal resistance and no isolation port.
• The coupler has no loss (power is not radiated from the network or it is not converted to heat). The power distributor does not have a T-junction as in the simplest power divider case.
• Power dividers are mainly used for signal sampling so that you can measure the two characteristics of the signal (such as frequency and power). It is also used to distribute power to multiple antennas. Because it is bidirectional, it can be used as a power combiner. Couplers are used to capture a portion of the energy from the transmission line and sample the signal. This fragment is proportional to the transmitted energy and can then be measured without stopping the flow. It can also be used as a means to insert another signal in the system.
