Time folding power combining circuits convert a continuous wave into a pulsed wave of greater peak power. Such a circuit may comprise: a switch which receives a continuous wave signal as input, and outputs first and second pulsed wave signals along first and second signal paths, respectively, said switch being configured to repeatedly switch connection back and forth between the input and the outputs of the first and second signal paths in a plurality of time frames; a delay line in the second signal path configured to introduce a time delay to the second pulsed wave signal in the second signal path such that the first pulsed wave signal in the first signal path and the time-delayed second pulsed wave signal in the second signal path substantially align in the same time frames; and a combiner, which receives the first pulsed wave signal in the first signal path and the time-delayed pulsed second wave signal in the second signal path as inputs, and combines them into a single combined pulsed wave signal as output.