Abstract: An analog transponder processor for use in a multibeam satellite receiving input beam signals and transmitting output beam signals has an input switch matrix, channel processors, and an output switch matrix. The input switch matrix power divides input beam signals into sets of input beam signals. The channel processors each receive at least one input beam signal from the input switch matrix. The channel processors filter the input beam signals into channel signals. Each of the channel signals corresponds to a respective channel of the input beam signals. The channel processors change the frequency of at least one channel signal such that the at least one channel signal corresponds to a different channel than the respective channel of the input beam signals. The output switch matrix combines the channel signals into output beam signals.

Abstract: Transponder systems are disclosed for routing signals from a plurality of input frequency channels at each of a plurality of receive antennas to a plurality of output frequency channels at each of a plurality of transmit antennas. The routing is preferably processed at an intermediate frequency. A plurality of bandpass filters are coupled to each receive antenna to define input signal paths. First and second mixers are positioned in series with each bandpass filter. A mixing signal at the first mixer adjusts the frequency of a selected one of the input signals to pass it through the bandpass filter and onto the respective input signal path. A mixing signal on the second mixer translates the frequency of that input signal to have a frequency order in the intermediate frequency band that corresponds with the frequency order of a selected one of the output frequency channels at its respective transmit antenna. Each of the transmit antennas is coupled to a common signal path of an adder.

Abstract: Input RF signals to a transponder, such as a communications satellite, are down converted to a lower intermediate frequency (IF) that is common for each different channel. The channel signals are all processed at the common IF, and then up converted to different respective transmission frequencies. This allows for a down conversion/signal processing/up conversion unit design that is the same for each channel (except for frequency and gain values), and facilitates the use of inexpensive available standard components as well as low bandwidth channel filters. An improved phase noise cancellation phase lock loop (PLL) is preferably used to generate tuning signals used in the up and down conversion processes. The PLL includes two loop mixers, with the down and up conversion mixing signals taken respectively from the inputs to the first and second loop mixers. The first and second loop mixers receive mixing signals at frequencies (T-R) and (T-IF-N.multidot.