The MAS 5 multiport antenna system is designed for installations where space is at a premium and communication requirements are for several circuits simultaneously having a variety of path lengths. It provides five independent antenna modes. Two of these modes are NVIS modes for short range skywave circuits; two are low angle modes for medium range circuits; and the fifth port is a high gain rotatable log periodic antenna for long range circuits. The relatively small installation area together with the five independent antenna ports makes the MAS-5 ideally suited for congested antenna fields or sites where space is severely limited.
The MAS-5 Multiport Antenna system combines the four omnidirectional port capability of the SPQ-330 with the Rotatable Log Periodic Array (RLPA) features of LPH-24 to provide a truly five port antenna system occupying the space normally required for a single antenna. All five ports may be used independently for transmit or receive. The RLPA has high gain, azimuth selection (computer control optional) and permits communication between a fixed site and mobile station such as ships and aircraft. It also features a torque tube and base-located rotator thereby providing high reliability and easy accessibility for inspections and maintenance. The spiral is a four-arm equiangular design wound on a pyramidal structure formed by the center support tower and four catenaries. It is fed using an AP four-port hybrid and is protected under US Patent 5189434.