APSK Transmission Experiments over 12GHz-band Satellite Channel Compared TWTA and SSPA

120-W Ku-Band GaN SSPA with Diode Linearizer for Future Broadcasting Satellites

“…Figure 2 shows the block diagram of the satellite channel model in our simulation, which is mainly made up of a transmitter, satellite transponder, and receiver. The dashed line in the figure outlines the configuration of a typical satellite transponder, which consists of an input multiplexer (IMUX) filter, a TWTA, and an output multiplexer (OMUX) filter [17], [18]. The role of the satellite transponder is to filter a single carrier out of the uplink signals, amplify it, and send it to the service area.…”

“…block in the receiver means an adaptive equalizer based on the least-squares-error criterion [19]. Figure 3 shows the AM/AM and AM/PM characteristics of the TWTA, which are actual measurements from indoor tests [17]- [19]. In the case of the 120-W-class TWTA, the normalized output power of 0 dB corresponds to 120 W (50.8 dBm).…”

“…Thus, there is a trade-off between the gain of the amplifier and the linearity. Figure 4 shows the amplitude and group delay characteristics of the IMUX and OMUX filters, which are also actual measurements from the indoor tests [17]- [19]. The role of the IMUX is to filter a single carrier out of the other adjacent broadcasting waves [21].…”

“…Figure 17 shows a block diagram of the transmission system of our experiments. The dashed line marks the area of the 12-GHz-band satellite transponder in the satellite simulator composed of hardware [17]- [19]. We conducted transmission tests by replacing the TWTA with the SSPA inside this satellite simulator and evaluated the differences in transmission performance in the following channel models:…”