Microwave devices is referred to as the work of a series of related devices in the microwave band. If the connection element, terminal device, matching element, the attenuation and phase shift element, shunt element, filter element. Through the circuit design, can use these devices are combined into a variety of specific effect of microwave circuits, microwave and microwave circuit together constitute the microwave system.
Classification of microwave devices
Microwave devices according to the structure can be divided into: waveguide, coaxial line, microstrip line.
According to the working waveform is divided into: single mode, multimode device device.
According to the network port can be divided into: port two port network, network, network, three port four port network.
The effect of microwave devices
The 1 terminal load element: a port reciprocal elements, including short circuit load, load matching and mismatching load.
1) short circuit load, requirements:
(1) ensure that the small loss,
(2) when the piston moves, contact loss of small changes;
(3) and high power, the piston and the waveguide wall should not produce spark phenomenon.
Can be used as modulators, pure reactance element.
Structure: contact, choke type (sheet metal).
2) matched load
All absorbed elements the main technical indicators of input power: the frequency of F, the input in the Bobbi, power capacity. As the matching criterion, the equivalent antenna, absorbing load etc..
3) mismatched load
As a standard mismatched load. Absorb a part of power, reflecting a part of power.
2 microwave connection element: two port the reciprocity element. Mainly includes: waveguide connector, attenuator, adapter, phase shifter. The role is to connect different microwave components into a complete system.
Without the basic properties of consumption of reciprocal two port network:
1) if a port match, another port automatic matching;
2) if the network perfectly matched, it is completely transmitted, or on the contrary;
3) phase of S11, S12, S22, only two are independent, known among the two phase, the third phase can be determined.
A 3 impedance matching element
Diaphragm (inductive diaphragm B boundary)
Capacitive diaphragm (band)
Screw tuner (single screw, twin screw, three screw, four screw – principle with the stub tuner, but screw only capacitor).
Application of microwave devices
Microwave device has the advantages of high efficiency, easy to use, has important significance for radar, communications, electronic warfare and electronic equipment to achieve full solid state. Microwave oscillator (microwave) are important devices in the microwave system, is the electronic equipment of the heart, have a direct impact on its performance. For example, in the high power microwave weapons systems, high power microwave oscillator determines the killing efficacy; in radar systems, microwave oscillator determines the radar range.