PM & DML Microwave Links – Digital & Analogue

ABE links in the "PM" Series (both analogue and digital versions) and in the "DML" Series (only digital) operate in all the microwave frequency bands commonly used for STL (Studio to Transmitter Link), Contribution / Distribution Networks and Mobile Communications.

These have been designed for the transmission of high quality TV, Audio and Data signals using digital QPSK-QAM or OFDM modulation schemes or analogue 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 contact us.

The links are now available in the following 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 analogue 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 analogue 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 accumulated 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 analogue 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 analogue 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 (synthesised with "L" band IF), extremely compact in size, flexible and competitively priced (in comparison with analogue systems). They are provided with the QPSK modulation scheme as standard (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-2 Encoders and Decoders.

ABE's Microwave Links has been manufactured since 1982, with over 5,000 systems supplied worldwide. Options and accessories available with the "PM" series Links include parabolic antennas, multiplexers, tripods for mobile use, telemetry interface (for a detailed description see the Network Manager section), cables, waveguides, connectors, and so on.

Please download the appropriate brochure:

• DML series Digital Microwave Links (466k)
  
• PM series Microwave Links (644k)

Related Equipment:

• QPSK (DVM-1000/S) Modulator (435k)
  
• 16QAM (DVM-1000/C) Modulator (379k)
  
• MPEG-2 Encoder/s + QPSK (DME-1000/S) Modulator (531k)
  
• MPEG-2 Encoder/s + 16QAM (DME-1000/C) Modulator (532k)
  
• MPEG-2/DVB (4:2:0) Professional Single Ch. IRD (307k)
  
• “Lâ€? Band Digital Modulator + MPEG-2 Encoder (DME-1000/SL) (464k)
  
• IF Converter Module 70 to 985MHz (91k)
  

Please download related Technical Papers & Software:

• MPEG-2 Encoding and most common profiles (47k)
  
• Upgrading analogue TV Microwave Links for digital operation (155k)
  
• QPSK modulator settings (DVM 1000 – DME series) (72k)
  
• TV digital microwave link (configuration example) (340k)
  
• Digital TV broadcasting handbook (954k)
  
• Paper on Digital Microwave Links for TV; A comparison of the available technologies (192k)
  
• RTI MS Word Microwave Link Requirements Form (79k)

Free software for calculating microwave link budgets and other RF requirements.

Free Software Download:

• Free RF calculator software (4.53Mb)

For more information and a quotation please visit our contact page.