M-Press Systems (M) Sdn. Bhd.
Industrial Microwave-, Plasma-, RF- and Control-Systems

Waveguide Components

We offer a broad range of waveguide components, either for replacement or for the design of new systems. These components are available in different waveguide sizes (for the specifications of selected waveguides please refer to this table) and in different materials, i.e. aluminium, brass, copper and stainless steel. Please note that we manufacture all waveguide components in-house and therefore can offer you to design and machine components exactly to your specifications, whether you need only a single piece or medium to large quantities for your own OEM design.

Waveguide launchers

Waveguide launchers, commonly just called launchers, are the mounting points for the Magnetrons and serve to couple the microwave energy from the Magnetron's antenna into the waveguide system. Launchers are specifically designed for a Magnetron, not only to match it's mechanical dimensions, but also to provide the required VSWR and phase in order to ensure optimum operation and efficiency of the Magnetron. Please note that for most high-power Magnetrons (Po ≥ 30 kW) the electromagnets and pole pieces are not integral parts of the Magnetrons, but are separate components fitted to the launcher, and must be ordered separately.


Circulator Circulators are passive devices with usually 3 waveguide ports. They are non-reciprocal, meaning that depending on the direction in which the microwave energy is transmitted it is diverted to one port or the other. Circulators are a main component of isolators, please see below.

Dummy loads

Dummy load Dummy loads absorb microwave energy by converting it into thermal energy, which is then dissipated. While for smaller power levels up to a few 100 W dry loads, which dissipate the absorbed microwave energy via a heat sink, are suitable, most industrial microwave systems are using water loads which, depending on their size and design, are capable of continuously absorbing power in the range of 100 kW and more. Dummy loads are normally used as a test load for microwave generators or as a main component in isolators.


Isolator Isolators are consisting of a 3-port circulator and a dummy load (in industrial applications usually a water load). While the dummy load terminates 1 of the 3 ports, the other 2 ports are connected to the Magnetron (usually via the waveguide launcher) and to the waveguide connecting the generator to the applicator. Isolators protect the Magnetrons from microwave energy reflected backwards from the applicator, otherwise this energy would increase the Magnetron's temperature and might cause moding. While for Magnetrons with an output power below 6 kW isolators are strongly recommended, they should be considered a must for output powers of 6 kW and above.

Stub tuners

Auto tuner Stub tuners are waveguide pieces which contain 3 metal stubs arranged along the centre line of the waveguide. Adjusting the penetration depth of the metal stubs into the waveguide changes the characteristic impedance on either side of the tuner, and therefore they are used to match the impedance of the waveguide system to the impedance of the applicator. This ensures maximum energy transfer, minimises reflections and avoids arcing in high power applications. Stub tuners are available as simple manual tuners as well as fully electronically controlled auto-tuners, which are used when the load impedance varies considerably over time, e.g. in certain plasma applications.

Directional couplers

Directional coupler Directional couplers are either 3-port (single directional couplers) or 4-port (dual directional couplers) waveguide elements that couple a fraction of the microwave energy transferred between the main ports to the measuring ports. By connecting a suitable microwave detector to the measuring ports it is therefore possible to measure the actual energy transferred within the waveguide. They are called directional because only microwave energy travelling into a certain direction is coupled to the respective measuring port(s). Depending on the mounting direction a single directional coupler can therefore either measure incident or reflected power, while a dual directional coupler can measure both values at the same time. Directional couplers are characterised by there coupling factor, usually expressed in decibels [dB].

Other waveguide components

E-H-tuner Other waveguide components available from us include straight waveguides, flexible waveguides, E-bends and H-bends, coax transitions, vacuum transitions and others. If you have specific requirements please contact us.

Specifications of selected waveguides

Name according to standard:Inner dimensions:Operating range:
RETMAIEC 153BSA-side [mm]B-side [mm]f [MHz]Band
WR975R9-247.65123.82760 - 1150L
WR430R22WG8109.2254.611720 - 2610L, S
WR340R26WG9A86.3643.182170 - 3300S
WR284R32WG1072.1434.042600 - 3950S