Design of Waveguide Microwave Pulse Compressors Using Equivalent Circuits

Design of Microwave Pulse Compressors Using Small Form-Factor Waveguide Cavities

“…An efficient method is to calculate the scattering matrix of the turn by using the single T-junction equivalent circuit [16]. This approach is adequately accurate and much faster than full-wave simulation [9], [14].…”

“…6. Essentially, this circuit is identical to the one for the simple case of a straight-cavity MPC (SMPC) as it is presented in [9], [14]. In brief, [14] uses an iterative procedure to calculate the optimal values for the waveguide cavity length, the opening of the inductive iris and the length of the short circuit at the output port of the compressor.…”

“…Due to this fact, longer pulses would need inconveniently long cavities. For example, 10 ns pulses at 1.3 GHz roughly need a 1 m long WR-650 waveguide cavity [8], [9]. This length explodes to multiple meters, when tenths of ns are necessary.…”

“…Note that the MPC output pulse duration depends both on the group velocity and the physical length. Thus, even the migration to higher frequencies would not overcome the aforementioned limitation [8], [9].…”

“…However, due to the intuitive design there is no guarantee that the overall gain that was achieved is the maximum possible. Such a gain optimization becomes a critical issue, since the increase of the MPC electrical length inherently suppresses the cavity gain [8], [9]. A simple yet effective approach to optimize the dimensions of a waveguide based MPC and maximize the cavity gain has been presented in [9], [14] and [15].…”