Abstract: A frequency-hopping intrapulse frequency modulation Loran-C navigation pulse technique, preferably using a flat-topped pulse shape and a novel 16-ary phase hopping scheme, and a novel improved high-power solid-state switch for dynamic antenna modulation tuning.

Abstract: A frequency-hopping intrapulse frequency modulation Loran-C navigation pulse technique, preferably using a flat-topped pulse shape and a novel 16-ary phase hopping scheme, and a novel improved high-power solid-state switch for dynamic antenna modulation tuning.

Abstract: Frequency modulation switching apparatus for rapidly increasing and decreasing the frequency within radio-frequency pulses of radio wave pulse trains transmitted by an antenna having series inductance and capacitance, the apparatus having, in combination, a solid state four-terminal rectifier bridge circuit with opposing pairs of bridge terminals connected with one pair of opposing terminals shunting said inductance and said capacitance; and series-connected staturable and linear inductors and an SCR switch connected between the other pair of opposing terminals of the bridge circuit, whereby the high-speed triggering of the SCR on effects corresponding high-speed frequency increasing or decreasing of the frequency within the radio-frequency pulse to provide the desired frequency modulation therein

Abstract: A method and apparatus for increasing the potential digital bit data rate potential for communication-to-be-added to Loran-C radio-frequency pulse navigation transmitters and the like without affecting the navigation capability and integrity of the system, involving frequency-sweeping the pulse carrier frequency between critical lower and upper limits with respect to the pulse carrier frequency during the parts of each pulse following the initial part used for navigation timing.

Abstract: A novel loop antenna containing a thin-walled ferrite box or other hollow; magnetic core structure of high permeability (considerably greater than 100), particularly useful for crossed loop antennas, and of optimal geometry and configuration for minimum volume, weight and space.

Abstract: An improved pulse generator for RF pulse generation in tuned loads, employing full cycle generators formed by pairs of parallely connected half-cycle SCR-triggered capacitor-charging and discharging generators each having its own separate d.c. power supply, and wherein reverse capacitor voltages are clamped by diode connecting the capacitor of each half-cycle generator to the power supply of the other half-cycle generator.

Abstract: A technique for optimizing the impedance match between a plurality of pulse generators and a high-Q tuned load by equally advancing and retarding the phase of equal groups of pulse generator modules with respect to the load voltage. The sum output current is in phase with the coupling network voltage and produces alternating pulse generator sinewave outputs of successive plus and minus equal phase shifts with respect to the load voltage.

Abstract: A novel magnetic crossed loop antenna system is provided for use with radio navigation signals, such as provided by two or more Loran-C transmitters, and in which each loop antenna is rapidly switched between the receiving channel and that of the other loop-antenna to enable the selection of one channel with the strongest signals from both transmitters, and through tuning the antenna to the Loran-C frequency and providing rate compensation and feedback to the antenna, optimum signal-to-noise ratio, sufficiently wide bandwidth to ensure time delay stability and attenuated amplifier noise are achieved, enabling greatly improved location and tracking.

Abstract: A relatively wide d.c. pulse generating system providing rise times normally attainable only with much narrower pulse width generation, comprising a plurality of sequentially operated groups of d.c. pulse generating modules achieving the combination of zero current SCR-switching and rapid magnetic switching and providing very high reliability and efficiency, and with the feature of continuously variable pulse width control and overall amplitude contouring, as for controlling applications such as plasma ion implantation where non-uniform contours of ion depth penetration normally would otherwise obtain.

Abstract: The invention relates to a novel high-speed actuated high-voltage RF switch for such purposes as the cold switching of short very high current RF pulses in applications such as solid-state Loran-C transmitters and the like, as for switching between coupling/output networks thereof. The switch comprises planar upper and lower unconnected pairs of longitudinally extending input and output bus strips electrically connectable by the transverse insertion of planar link strips slightly separated therefrom and the rapid compression thereof against the adjacent end portions of the unconnected input and output bus strips, enabling rapid switching absent wear of the contact surfaces, but with the provision of adequate spacing for high voltage operation and adequate contact pressure to eliminate current arcing.

Abstract: A method of and apparatus for two-way radio meteor scatter communication amongst mobile transceiver-equipped terminals and fixed meteor scatter base terminal(s) that comprises communicating high volume point-to-point inbound information from the mobile terminals to the base terminal(s) and outbound information from the base terminal(s) to particular mobile terminals by radio meteor scatter, and broadcasting outbound information from the base terminal(s) to many mobile terminals by supplemental Loran communications short messages modulated upon Loran radio positional and navigation transmissions.

Abstract: A dynamic antenna tuning system particularly adapted for VLF frequency-shift (as opposed to on-off) keyed transmitters, employing saturable magnetic switching amplifiers providing variable tuning inductance between the antenna and transmitter and controlled to effect a gradual and not abrupt switching of the radio frequency during on-off transitions to enable narrow VLF frequency spectrum operation.

Abstract: This disclosure is concerned with a technique and apparatus for reducing CW and other inband interference in a broad bandwidth RF pulse navigation system to inobtrusive noise through the use of pulse-position random modulation, including, where desired, superimposed random phase modulation, with signal-random modulation code cross-correlation in reception.

Abstract: This disclosure is concerned with generating in a plurality of successive modules, simultaneously and repetitively, a plurality of similar, simultaneous, narrow high voltage pulses, and adding them together in a way that the failure of mis-timing of any module will not prevent the continued operation of the resultant pulse generation. The result is attained by appropriate interconnection of the modules, each of which embodies triggered charging and preferably magnetic pulse-compression and step-up operations.

Abstract: This disclosure is directed to SCR charging or other energy-switching circuits provided with priming and carrier sweep-out networks and the like that normally incur energy losses in the priming and sweep-out processes, wherein such losses are obviated by transferring energy resulting from such processes back to the power supplies.

Abstract: The disclosure is concerned with enabling modular power converter systems, including RF generators or transmitters involving such conversion, employing switching components such as SCRs in the power conversion, to fail in a soft manner as a result of transient electrical or other disturbances so as to permit continued system operation, through the use of individual module d.c. power supplies and circuit design that insures inverter module high output impedance even under SCR failure conditions and that mitigates against SCR failures caused by changes in load phase angle.

Abstract: This disclosure deals with the use of groups of unambiguous radio-frequency pulse transmissions for Loran C and similar radio navigation, eliminating cycle-selection ambiguity and reducing the required power level for transmission.

Abstract: A high-Q, pulse transmitting antenna system is disclosed, as of the Loran type, wherein a simple solidstate circuit, employing mainly passive elements serves, during quiescent periods between transmissions, to introduce loss into the antenna circuit, thereby selectively to lower the Q of the antenna circuit and thus prevent spurious oscillations therein during such quiescent periods.

Abstract: This disclosure relates to the generation of RF pulses, generally in groups of pulses, through the use of a plurality of sequentially discharged power supplies, the successive discharge bursts of which are fed to a plurality of successive cycle-producing pulse generators, also sequentially triggered to generate a predetermined number of cycles of RF pulse for each such burst.