SEMCO’s Airborne Digital Transmitter products are multi-mode digital transmitters that are ideal for airborne and other transmitter applications in L, S and C-Band and requiring support of legacy PCM/FM modulation modes as well as the more spectrum efficient ARTM Tier I SOQPSK-TG and Tier II Multi-h CPM. Space Time Code (STC) and Low-Density Parity Check (LDPC) encoders are available in overall transmitter product design, as is Viterbi Forward Error Correction (FEC) encoders.
SEMCO’s transmitter products are designed and manufactured by Emhiser Research, Inc., who has been in the airborne transmitter business for over 40 years and is an innovative pioneer in the design and development of transmitters for the Department of Defense, prime contractors and various space agencies. These transmitters are designed for harsh military environments, with virtually all transmitters range qualified. Emhiser Research holds over 40 patents as an example of their industry-leading capabilities.
As authorized re-seller and integrator for these transmitter products, SEMCO offers multi-mode digital transmitters that range in size from 1.3 cubic inches to 27 cubic inches, provide outstanding size-to-power ratios and 2W, 5W, 10W and 20W RF power output levels. Single frequency or channelized configurations with programmable 0.25, .5 and 1 MHz steps are provided, as well as single band (L, S or C), dual band (any two of L, S and C) and tri-band (L, S and C).
The spectral mask of all multi-mode Transmitter products is IRIG 106-20 Tier II phase noise compliant and offers programmable data rates from 500 kbps to 23 Mbps (PCM/FM) and 500 kbps to 40 Mbps (SOQPSK-TG and Multi-h CPM). In addition to this available embedded modulation, external modulation capability in TTL and RS422 formats is provided.
All transmitters are DC-coupled for optimum performance and have an efficient maximum power draw of 900 mA to 3.8 A at 28 VDC, depending on output power. These transmitters exhibit exceptional DC-to-RF Conversion Efficiency which, for example provides the flexibility of replacing older 10W transmitters with a new 20W transmitter at the same or less current draw.
Unlike other industry transmitter designs, all of these transmitter products use an isolator circuit in the last RF output stage to mitigate any transmitter damage or reduced RF power output resulting from any impedance mismatch encountered during transmitter installation, integration and operation. This design further reduces or eliminates the generation of intermodulation products when there is another transmitter in the nearby vicinity.
Let us provide a comparison of performance and price with other industry transmitter providers – you will be very pleased with the result.