Dual direction hybrid coupler series
● High directivity.
● Good coupling flatness.
● Small size.
● Light weight and high power.
Directional coupler is a kind of microwave device widely used in microwave system. Its essence is to distribute the power of microwave signal in a certain proportion.
Directional couplers are composed of transmission lines. Coaxial lines, rectangular waveguides, circular waveguides, striplines and microstrip lines can all constitute directional couplers. Therefore, from the perspective of structure, directional couplers have a wide range of types and great differences. However, from the perspective of its coupling mechanism, it can be divided into four types, namely, pinhole coupling, parallel coupling, branching coupling and matching double T.
A directional coupler is a component that places two transmission lines close enough to each other so that the power on one line can be coupled to the power on the other. The signal amplitude of its two output ports can be equal or unequal. A coupler that is widely used is 3dB coupler, and the amplitude of the output signals of its two output ports is equal.
Directional coupler is a directional power coupling (distribution) element. It is a four port component, usually composed of two transmission lines called straight line (main line) and coupling line (secondary line). Part (or all) of the power of the straight line is coupled to the coupling line through a certain coupling mechanism (such as slots, holes, coupling line segments, etc.) between the straight line and the coupling line, and the power is required to be transmitted only to one output port in the coupling line, while the other port has no power output. If the wave propagation direction in the straight line becomes opposite to the original direction, the power output port and the non power output port in the coupling line will also change accordingly, that is, the power coupling (distribution) is directional, so it is called directional coupler (directional coupler).
As an important part of many microwave circuits, directional couplers are widely used in modern electronic systems. It can be used to provide sampling power for temperature compensation and amplitude control circuits, and can complete power distribution and synthesis in a wide frequency range; In the balanced amplifier, it is helpful to obtain good input and output voltage standing wave ratio (VSWR); In the balanced mixer and microwave equipment (e.g., network analyzer), it can be used to sample the incident and reflected signals; In mobile communication, use.
90 ° bridge coupler can determine the phase error of π/4 phase shift keying (QPSK) transmitter. The coupler is matched to the characteristic impedance at all four ports, which makes it easy to be embedded in other circuits or subsystems. By using different coupling structures, coupling mediums and coupling mechanisms, directional couplers suitable for different requirements of various microwave systems can be designed.