ABE’s Links in the “PM” Series (both digital and analog versions) and in the “DML” Series (only digital) operate in all the microwave frequency bands commonly used for STL (Studio Transmitter Link), Contribution/Distribution Networks and Mobile Communications.
These have been designed for the transmission of high quality TV, Audio and Data signals using digit al QPSK-QAM or OFDM modulation schemes or analog frequency modulation.
Standard production includes models operating in the 2GHz, 3-5 GHz, 7-8GHz, 10GHz, 14GHz and 20-24GHz bands; for other bands, please consult ABE’s Sales Office.
The Links are now available in the following choices of configurations:
• Fixed indoor version - housed in standard 19’’ rack drawers, comprising the IF Modulator, Converter-Transmitter, Converter-Receiver, and the IF Demodulator.
• Outdoor version (fixed or mobile), with Modulator and Demodulator in standard 19’’ rack mounting chassis and RF Heads for Transmitter and Receiver in outdoor sealed units, fitted on tripods, or in mast housings to be mounted near the antennas.
Digital versions (especially with the very robust QPSK modulation scheme) offer many notable advantages in comparison with the analog systems:
• A single Link may be used to carry 4 (or more) video/audio program channels in the same RF occupied bandwidth of a single program analog Link.
• Link performance does not degrade progressively as the receiver input reduces, but remains constant down to a very low threshold. In practice, the receiver input range is increased by around 20dB, allowing the Link to maintain high performance with increased fade-margin, or to use lower RF power or smaller antenna sizes to cover the same distance.
ABE’s Microwave Links are designed to make Contribution/Distribution networks, with 70MHz IF (non demodulating) connections between the links or through the digital ASI interface, so that the signal (Transport Stream) will be demodulated, corrected and regenerated at every hop, avoiding problems of accumulating signal deterioration when a large number of links are employed in a chain (one after the other).
ABE’s “PM” Series Links feature both single frequency conversion (with 70MHz IF) and double frequency conversion (used in tuneable synthesised transmitters and receivers to provide channel selection on pre-programmed frequencies).
The analog modulator and demodulator are designed with sufficient bandwidth capability to handle a single video channel with up to four audio, data, or service channels.
The microwave links in the “PM” series are supplied without amplitude limiters and with high stability/low phase noise local oscillators, to be “Digital Ready” when supplied with analog modulators and demodulators. These links can be later upgraded with digital QPSK/QAM modems, thus enabling future proof investment to satisfy both today’s and tomorrow’s needs.
The “DML” Digital Microwave Links Series are frequency- agile (synthesized with “L” band IF), extremely compact in size, flexible and competitively priced (in comparison with the analog systems). They’re provided with QPSK standard modulation scheme (input bit-rate up to 48Mbit/s), but are also available in versions with 8 PSK and 16 QAM modulation schemes with higher bit-rate capacity.
Digital Modulators and Demodulators are normally equipped with an ASI interface, but can also include one or more MPEG Encoders and Decoders.
ABE’s Microwave Link has been manufactured since 1982, and over 6000 systems have been supplied worldwide.
Options and accessories available with the “PM” series Links include parabolic antennas, multiplexers, tripods for mobile use, remote control interface, cables, waveguides, connectors, and so on.