Satellite communications have been used for a variety of communications. For example, a TV broadcasting system using a satellite has been developing in recent years. In such a satellite TV broadcasting system, a TV receiving system requires a microwave receiving antenna for receiving satellite TV broadcasting waves and a satellite receiver, in addition to a conventional TV receiver. The microwave receiving antenna apparatus generally comprises a wave collector such as a parabolic reflector. The satellite receiver converts signals received by the microwave receiving antenna apparatus to signals suitable for the TV receivers.
Conventionally, the microwave receiving antenna apparatus has been fixed to the ground or a building through a post. A direction adjuster is provided between the microwave receiving antenna apparatus and the post for adjusting the direction of the microwave receiving antenna apparatus to a selected satellite. The direction adjuster is adapted for adjusting both the elevation angle and the azimuth angle of the microwave receiving antenna apparatus for the selected satellite.
FIG. 1 shows an example of the conventional microwave receiving antenna apparatus. As shown in FIG. 1, the microwave receiving antenna apparatus comprises a microwave receiving antenna unit 100, a post 102 and a direction adjuster 104.
A bottom end of the post 102 is fixed to the ground 106 with concrete 108. The microwave receiving antenna unit 100 is mounted to a top end of the post 102 through the direction adjuster 104. The direction adjuster 104 adjusts the elevation angle and the azimuth angle of the microwave receiving antenna unit 100 for a selected satellite.
The microwave receiving antenna unit 100 generally includes a parabolic reflector 100a, an outer unit 100b and an arm 100c. Further the outer unit 100b comprises an antenna element, i.e., a primary feeder 100d and a low noise blockdown converter (referred as LNB converter hereafter) 100e. The primary feeder 100d is located on the offset focus of the parabolic reflector 100a for inducing 12 GHz band microwave radio signals corresponding to broadcast waves transmitted by satellites. The LNB converter 100e is coupled to the primary feeder 100d for carrying out both an amplification of the received signals and a frequency conversion of the signals to prescribed lower frequency band signals, e.g., 1 GHz signals.
The arm 100c is provided for supporting the outer unit 100b on the parabolic reflector 100a. The radio signals obtained by the outer unit 100b is coupled to a predetermined output terminal (not shown) equipped on the parabolic reflector 100a through the arm 100c. The output radio signals of the LNB converter 100e or the outer unit 100b are applied to a satellite receiver (not shown).
As is described above, the conventional microwave receiving antenna apparatus has been fixed to the ground. As a result, the microwave receiving antenna apparatus requires a relatively expensive installation cost. Furthermore, although a portable TV receiver has become popular in recent years, it is difficult to carry the satellite TV reception system to any place where users may travel.
A flat antenna apparatus such as a synthetic aperture array antenna apparatus for satellite TV reception also has been developed. Such a flat antenna apparatus can be moved relatively easily. However, a complete satellite TV receiving system including the flat antenna apparatus, a satellite receiver and a TV receiver has a relatively large volume and is heavy. Therefore, it is still difficult to carry the satellite TV reception system to any place where users may travel.