Frequency-phase coding device

A method for generating approximately orthogonal doppler-tolerant pulse-compression codes which suppress jamming comprising the steps of:

• generating a signal pulse of bandwidth B;
• delaying said signal pulse by a series of n-1 equal delays .tau. and taking a signal before each delay and after the last delay to yield n signals;
• filtering each of said n sequentially delayed signals by a different bandpass filter in a comb filter approximately covering said bandwidth B;
• phase coding each of said n filtered signals;
• and
• adding the n phase-coded signals to form an orthogonal signal pulse.

A doppler tolerant pulse-compression-code generator for generating approximately orthogonal codes comprising:

• means for generating a signal pulse of bandwidth B;
• delays means with n signal taps spaced by equal delays .tau. for delaying the pulse generated by said pulse generating means by a series of equal delay increments;
• n bandpass filter channels approximately covering said bandwidth B by means of n adjacent spectral bands;
• a switching matrix for connecting, in any desired order, each one of said n signal taps to a different one of said n bandpass filter channels, and
• means for adding the delayed signals from said n bandpass channels to form an expanded pulse.

A method for generating approximately orthogonal doppler-tolerant pulse-compression codes which suppress jamming comprising the steps of:

• generating a signal pulse of bandwidth B;
• delaying said signal pulse by a series of n-1 equal delays .tau. and taking a signal before each delay and after the last delay to yield n signals;
• switching each of said n sequentially delayed signals to a different bandpass filter in a comb filter in a first switching order;
• filtering each of said n sequentially delayed signals in the bandpass filter to which it was switched;
• adding the n delayed, filtered signals to form a first expanded signal pulse;
• and
• then switching each of said sequentially delayed signals to a different bandpass filter in the comb filter in a second switching order to yield a second expanded signal pulse approximately orthogonal to said first expanded signal pulse.