Category: Resonators and Waveguides

Waveguide Switch Design

Waveguide Switch Design: It is often necessary to prevent microwave power from following a particular path, or to force it to follow another path; as at lower frequencies, the component used for this purpose is called a switch. Waveguide Switch Design (or coaxial) may be mechanical (manually operated) or electromechanical (solenoid-operated). They can also be […]

Waveguide Mixers and Detectors

Waveguide Mixers and Detectors: As we know that ordinary transistor and tube RF amplifiers eventually fail at microwave frequencies, because of greatly increased noise, compared with their low-frequency performance. Unless a receiver is to be very low-noise and extremely sensitive (in which case special RF amplifiers will be used, then a mixer is the first […]

Waveguide Isolator and Circulators

Waveguide Isolator and Circulators: It often happens at microwave frequencies that coupling must be strictly a one-way affair. This applies for most microwave generators, whose output amplitude and frequency could be affected by changes in load impedance. Some means must be found to ensure that the coupling is unidirectional from generator to load. A number […]

Directional Coupler Waveguide

Directional Coupler Waveguide: We already know that a transmission-line Directional Coupler Waveguide. Its applications were indicated at the time as being unidirectional power flow measurement, SWR measurement and unidirectional wave radiation. Exactly the same considerations apply to waveguides. Several directional couplers for waveguides exist, and the most common ones will be described, including a direct […]

Cavity Resonators

Cavity Resonators: A cavity resonators is a piece of waveguide closed off at both ends with metallic planes. Where propagation in the longitudinal direction took place in the waveguide, standing waves exist in the resonator, and oscillations can take place if the resonator is suitably excited. Various aspects of cavity resonators will now be considered. […]

Impedance Matching and Tuning in Waveguide

Impedance Matching and Tuning in Waveguide: We know that suitably chosen series or parallel pieces of transmission line had properties which made them useful for providing resistive or reactive impedances. It is the purpose of this section to show how the same effects are achieved in waveguides, and again transmission-line equivalents of waveguide matching devices […]

Waveguide Junctions

Waveguide Junctions: When it is required to combine two or more signals (or split a signal into two or more parts) in a waveguide system, some form of multiple junction must be used. For simpler interconnections T-shaped junctions are used, whereas more complex junctions may be hybrid T or hybrid rings. In addition to being […]

Waveguide Coupling

Waveguide Coupling: When waveguide pieces or components are joined together, the Waveguide Coupling is generally by means of some sort of flange. The function of such a flange is to ensure a smooth mechanical junction and suitable electrical characteristics, particularly low external radiation and low internal reflections. The same considerations apply to a rotating coupling, […]

Methods of Exciting Waveguides

Methods of Exciting Waveguides: In order to launch a particular mode in a Methods of Exciting Waveguides, some arrangement or combination of one of more antennas is generally used. However, it is also possible to couple a coaxial line directly to a waveguide, or to couple waveguides to each other by means of slots in […]

Circular Waveguide

Circular Waveguide: It should be noted from the outset that in general terms the behavior of waves in circular waveguide is the same as in rectangular guides. Analysis of behavior: The laws governing the propagation of waves in waveguides are independent of the cross-sectional shape and dimensions of the guide. As a result, all the […]