Radio frequency combiner
A multichannel combiner formed from 2 to 1 combiners, wherein: a first input channel of each 2 to 1 combiner is connected to the output of a settable-gain amplifier of a signal to be combined; all 2 to 1 combiners are electrically connected in series; and an output of a first 2 to 1 combiner defines an output of the multichannel combiner.
1. A multichannel combiner formed from 2 to 1 combiners, wherein:
all 2 to 1 combiners are electrically series-connected;
a first input terminal of each 2 to 1 combiner is connected to the output of a settable-gain amplifier of a signal to be combined, wherein the gain, in dB, of an amplifier of rank i is, neglecting losses, provided by the following relation:
A i =A 1 +10.log(2 i-2 ),
where A 1 stands for the gain of the amplifier associated with the first channel, possibly increased according to the loss expected in the circuit; and
an output of a first 2 to 1 combiner defines an output (OUT C ) of the multichannel combiner.
2. The combiner of claim 1 , wherein a second input of each 2 to 1 combiner receives a signal originating from the channel of previous rank.
3. The combiner of claim 1 , comprising as many 2 to 1 combiners as there are channels, the 2 to 1 combiner associated with the last channel having its second input loaded with an impedance (Z 0 ).
4. The combiner of claim 1 , comprising as many 2 to 1 combiners as there are channels minus one, the second input of the last combiner being connected to the output of the amplifier of the last channel.
5. A radio frequency transmission system comprising:
a transmitter capable of providing baseband signals on reception of radio frequency signals; and
at least three circuits, each defining a receive channel of a multichannel combiner formed from 2 to 1 combiners, wherein:
all 2 to 1 combiners are electrically series-connected;
a first input terminal of each 2 to 1 combiner is connected to the output of a settable-gain amplifier of a signal to be combined, wherein the gain, in dB, of an amplifier of rank i is, neglecting losses, provided by the following relation:
A i =A 1 +10.log(2 i-2 ),
where A 1 stands for the gain of the amplifier associated with the first channel, possibly increased according to the loss expected in the circuit; and
an output of a first 2 to 1 combiner defines an output (OUT C ) of the multichannel combiner.
6. The system of claim 5 , wherein each circuit further comprises a 2 to 1 splitter, the splitters of the different channels being electrically series-connected.