Potential Benefits of Dynamic Beam Synthesis to Mobile Satellite Communication, Using the Inmarsat 4 Antenna Architecture as a Test Example : Table 1

]>Potential Benefits of Dynamic Beam Synthesis to Mobile Satellite Communication, Using the Inmarsat 4 Antenna Architecture as a Test Example : Table 1

Table 1


Parameter	Value

Transmit	MHz
Receive	MHZ
Polarisation	RHCP
Number of antennas	Single Tx/Rx array fed reflector
Antenna type	Offset-fed paraboloidal reflector
Diameter	9 metres
F/D	0.53
Feed	120 helical elements, array diameter = 2.2 metres
Feed position	In front of focal plane
Beamformer	Digital Signal Processor, (DSP) with 15 multiport amplifier () blocks on transmit
Beam alignment	Beams aligned with fixed geographic cells
Beam reconfiguration	Beams reconfigured throughout the day to compensate for orbit inclination
Frequency reuse	Spatial diversity provides frequency reuse between beams

MPA blocks are used to distribute power more uniformly over the transmit amplifiers and hence increase their efficiency.