Dolph Microwave offers the high performance and high quality antenna feeds and RF networks to enable satcom antenna to offer the best performance. The antenna feed and RF networks are all components combination of antenna used for RF waves receiving and Transmitting. The antenna feed is portion of the antenna ranging from the Tx range to the receive range. The antenna feed includes transforming the RF waves into electrical signals and transmitting them to the receiver components. So it is namely used for the conversion RF waves into the electric signals.
Antenna feeds and RF networks as the heart of antenna system from Dolph Microwave is R&D by experienced our engineers who engaged into satcom and RF field for years. The components can be offered including OMT, duplixer, filter, phase shifter and feedhorn etc. covering different bands like C-band, Ku-band, Ka-band, S-band. X-band and required dual band etc. Any requirement, please contact sales@dolphmicrowave.com
For an antenna feed design, the efficiency, gain, and absolute gain are very important.
The feed impedance includes the loss resistance and the radiation resistance. The loss resistance is offered by the antenna components and the feed impedance is at the input of the antenna to the signal. Thus, the loss and the feed impedance must work together to achieve antennae feed normally work.
The radiation resistance is offered by the antenna to the radiation power namely the dissipated radiation power.
A feed horn is used to couple a waveguide which is used in radar, line-of-sight microwave transmission or radio astronomy. The feed horn minimizes the mismatch loss between the antenna and the waveguide. When the feed horn is used for a offset, parabolic or lens antenna, it is placed at the focal point of the reflector. The features of the feed horn is usually selected with the 3 dB points of the horn's radiation pattern falling on the edge of the reflector. When the shape of the antenna deviates from a dish, the feedhorn needs to be shaped accordingly to illuminate the antenna properly.
Antenna feed normally includes the components like OMT, phase shifter, rotary joint, feed horn, filter namely diplexer as well as bend waveguide etc, which is based on customer selection based on system application.
A Diplexer is a 3-port passive device that allows two different devices to share a common communication channel. It consists of two filters (Low Pass, High Pass or Band Pass) at different frequencies connected to a single antenna. Both the signals input to filter 1 and filter 2 need to be at different frequencies by a significant percentage, so that filters can easily sort them.
A Duplexer is a 3-port device that allows the transmitter and receiver to use a single antenna, while operating at the same/similar frequencies. It is a device that allows two-way communication over a single channel by isolating the receiver from transmitter while transmitting a pulse and isolating the transmitter from receiver while receiving a pulse, allowing them to share the same antenna. In a duplexer there is no direct path between the transmitter and receiver. It can be thought of as a circulator.
Phase Shifters are a critical component in many RF and Microwave systems. Applications include controlling the relative phase of each element in a phase array antenna in a RADAR or steerable communications link and in cancelation loops used in high linearity amplifiers.
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