Radio-frequency pulse generation system and method

Claim 3

A method as claimed in claim 1 and in which said timing is varied to produce phase-coding of successive pulses.

Claim 4

A method as claimed in claim 1 and in which continued oscillation of said pulse is prevented by critically damping said network and load at a time after the occurrence of the time required to peak said pulse.

Claim 5

A method as claimed in claim 1 and in which said load comprises an antenna circuit and the coupling network comprises a tuned circuit, and the further step is performed of tuning each of said circuits to said radio frequency.

Claim 6

A method as claimed in claim 4 and in which said pulses are Loran-type pulses with said generating steps being effected in groups of a plurality of pulses, with each group being phase-coded.

Claim 7

A method as claimed in claim 5 and in which a typical phase code is selected as + + or - - + - or + + - or + + or -, where + indicates zero degree radio-frequency carrier phase, -indicates 180* carrier phase, and + or - and - or + indicates that the pulses alternate in phase between + and - and between -and + from group to group.

Claim 8

A method as claimed in claim 5 and in which a typical phase code is selected comprising two groups of pulses as follows: + + - - + - + - +, and + - - + + + + + -, where + indicates zero degree radio-frequency carrier phase and - indicates 180* carrier phase.

Claim 9

A radio-frequency pulse generating system for producing pulses of predetermined pulse shape and having, in combination, a pair of similar radio-frequency pulse generator means each adjusted to produce a half-cycle only of radio-frequency current of opposite polarity to that of the other; means for controlling the timing of said generator means to produce a resultant complete cycle of radio-frequency current; coupling network means connected to each of the pulse generator means; a load connected to the network means; and means for adjusting the coupling network means and load to provide a resultant transfer function characteristic thereof yielding, upon impulse excitation by said complete cycle of said radio-frequency current from said pair of generator means, a pulse in said load of substantially said predetermined pulse shape, wherein the said complete cycle controls the first half cycles of the leading edge of the load pulse current and the said network and load characteristic controls the remaining half cycles thereof.

Claim 10

A radio-frequency pulse generating system for producing pulses of predetermined pulse shape and having, in combination, a pair of similar radio-frequency pulse generator means each adjusted to produce a half-cycle only of radio-frequency current of opposite polarity to that of the other; means for controlling the timing of said generator means to produce a resultant complete cycle of radio-frequency current; coupling network means connected to each of the pulse generator means; a load connected to the network means; and means for adjusting the coupling network means and load to provide a resultant transfer function characteristic thereof yielding, upon impulse excitation by said complete cycle of said radio-frequency current from said pair of generator means, a pulse in said load of substantially said predetermined pulse shape, wherein the said complete cycle controls the first half cycles of the leading edge of the load pulse current and the said network and load characteristic controls the remaining half cycles thereof.

Claim 11

A radio-frequency pulse generating system as claimed in claim 8 and in which means is provided for changing the relative timing of half cycles generated by the pair of pulse generator means to phase-code said pulses.

Claim 12

A radio-frequency pulse generating system as claimed in claim 9 and in which means is provided for controlling said pulse generator means to produce groups of pluralities of pulses, each group being phase-coded.

Claim 13

A radio-frequency pulse generAting system as claimed in claim 8 and in which there is provided means for critically damping said network means and load, and switching means for controlling the damping means to render the same effective at a time after the occurrence of the time required to peak said pulse.

Claim 14

A radio-frequency pulse generating system as claimed in claim 8 and in which load comprises an antenna circuit and said coupling network means comprises a tuned circuit, said circuits being tuned to said radio frequency.

Claim 15

A radio-frequency pulse generating system as claimed in claim 12 and in which said coupling network means is multiply tuned, further comprising circuit elements tuned to a frequency other than said radio frequency to modify the leading edge of said pulse.

Claim 16

A radio-frequency generating system as claimed in claim 8 and in which the coupling network means comprises a shunt-connected network, the impedance of which is adjusted to control the time required to peak said pulse.

Claim 17

A radio-frequency generating system as claimed in claim 14 and in which said shunt-connected network comprises at least one of (1) parallel capacitance-inductance tuned to said radio-frequency to provide a predetermined substantially cosine-wave pulse shape, (2) said parallel capacitance-inductance connected with series inductance to modify said cosine-wave pulse shape to approach a sine-wave shape, (3) substantially only capacitance further to filter out harmonics from said pulse generator means, and (4) substantially only inductance, the substantially only capacitance and only inductance producing pulse shapes closer to a sine-wave.

Claim 18

A radio-frequency generating system as claimed in claim 15 and in which means is provided for phase-coding said groups of pulses.

Claim 19

A radio-frequency generating system as claimed in claim 16 and in which said controlling means comprises antenna output current processor means connected to sample the output of said antenna means and to reference timing and amplitude means, time-multiplexed computer controlling means connected to said processor means and feeding pulse control means in turn connected with the pair of pulse generator means to interface with and control the same.

Claim 20

A radio-frequency generating system as claimed in claim 17 and in which said pulse control means is also connected with antenna tuner means for controlling the tuning of said antenna means.

Claim 21

A radio-frequency generating system as claimed in claim 17 and in which there is provided means for critically damping said network means and antenna load, and switching means for rendering the damping means effective at a time after the occurrence of the time required to peak said pulse.

Claim 22

A radio-frequency generating system as claimed in claim 8 and in which means is provided for controlling the amplitude of successive half-cycles of radio-frequency current to vary the envelope of the said leading edge.