Transmission of electronic information by pulse position modulation utilizing low average power

Art electrical circuit for generating intermittent high frequency pulses of extremely brief duration, comprising:

• (a) a transistor having a base, emitter, and collector;
• (b) an inductor having one end connected to the base of said transistor;
• (c) a first resistor connected between the other end of said inductor and ground;
• (d) a charging capacitor coupled between ground and the collector of said transistor to form a series loop circuit with the base-collector conduction path of said transistor;
• (e) a source of bias voltage;
• (f) a charging resistor connected between said bias voltage source and the collector of said transistor, for biasing said transistor near its avalanche breakdown voltage as well as supplying a charge to said charging capacitor that may be discharged through said transistor;
• (g) a bias resistor connected between the emitter of said transistor and the other end of said inductor;
• (h) a coupling capacitor coupled to the emitter of said transistor for applying intermittent triggering pulses thereto to produce an avalanche of current from said charging capacitor through said transistor in response to each said triggering pulse;
• (i) said charging resistor being selected of sufficiently large value to permit the recharging of said charging capacitor at only a slow rate so that the avalanche current discharged through said transistor in response to each pulse is essentially limited to the charge previously stored on said charging capacitor;
• and
• (j) the capacity of said charging capacitor, the maximum voltage applied to said charging capacitor, and the time interval between successive triggering pulses, being such as to avoid destruction of said transistor.

An electrical circuit for producing short, widely separated, high frequency pulses, comprising:

• (a) a transistor having a base, a collector, and an emitter, and having a forward conduction path extending from its collector to one of said base and emitter;
• (b) an inductor;
• (c) a delay line connected in a series loop circuit with said inductor and with said forward conduction path of said transistor;
• (d) circuit means for charging said delay line and holding said forward conduction path of said transistor near its breakdown condition;
• and
• (e) means for intermittently triggering said transistor into its breakdown condition,
• so that an avalanche of current then flows from said delay line through said forward conduction path into said inductor, and there appears across said inductor essentially a single sine wave cycle of voltage representing an oscillation frequency that is determined essentially by inductance value of said inductor and resistance value of said forward conduction path during conduction.

An electrical circuit for generating intermittent high frequency pulses of extremely brief duration, comprising:

• (a) a transistor having a base, a collector, and an emitter, and a forward conduction path from its collector through one of said base and emitter;
• (b) an inductor connected in series with said forward conduction path of said transistor;
• (c) voltage means for placing said forward conduction path of said transistor near its breakdown condition;
• (d) triggering means for actuating said transistor so that said forward conduction path breaks down at least momentarily and conducts in the avalanche mode;
• and
• (e) means associated with said voltage means for supplying a large current to said forward conduction path of said transistor during its breakdown mode, whereby said inductor produces essentially a single sine wave cycle of voltage representing an oscillation frequency determined essentially by the ratio of the inductance of said inductor to the resistance of said forward conduction path.

An electrical circuit for generating intermittent high frequency pulses of extremely brief duration, comprising:

• (a) a transistor;
• (b) circuit means biasing said transistor near its avalanche breakdown voltage;
• (c) an inductor and a capacitor coupled in a series loop circuit with the emitter-collector conduction path of said transistor;
• (d) a charging circuit for supplying a charge to said capacitor so that said capacitor will hold a charge ready to be discharged through said avalanche transistor;
• (e) means for applying intermittent triggering pulses to said transistor to produce avalanche conduction therethrough in response to each said triggering pulse;
• (f) said charging circuit also being adapted to re-charge said charging capacitor at a slow rate so that an avalanche current is discharged through said transistor which is essentially limited to the charge previously stored on said charging capacitor;
• (g) a transmitting antenna coupled in parallel with said inductor;
• and
• (h) the capacity of said charging capacitor, the maximum voltage applied to said charging capacitor, and the time interval between successive triggering pulses, being such as to avoid destruction of said transistor.

An electrical circuit for generating intermittent high frequency pulses of extremely brief duration and providing them to a twisted pair transmission line, comprising:

• (a) a transistor having a base, a collector, and an emitter, and a forward conduction path from its collector through one of said base and emitter;
• (b) a resistor and a twisted pair transmission line connected in a series loop circuit with said forward conduction path of said transistor;
• (c) voltage means for placing said forward conduction path of said transistor near its breakdown condition;
• (d) triggering means for actuating said transistor so that said forward conduction path breaks down at least momentarily and conducts in the avalanche mode;
• and
• (e) delay line means associated with said voltage means for supplying a large current to said forward conduction path of said transistor during its breakdown mode, whereby said resistor produces a voltage wave that is applied through said resistor to said twisted pair transmission line.

An electrical circuit utilizing a transistor in the avalanche mode for generating and transmitting very short and widely separated high frequency sine-wave pulses of electrical energy, comprising:

• a discharge circuit including a charging capacitor and an inductor connected in a first series loop path with two electrodes of the transistor that are part of a forward conduction path;
• a triggering circuit including a coupling capacitor connected to the other electrode of the transistor to provide an input for triggering it into its breakdown or avalanche mode;
• antenna means coupled to said inductor for transmitting electromagnetic energy into space;
• a recharging circuit including a charging resistor and a bias voltage source coupled with said charging capacitor into a second series loop path, said bias voltage source being capable of biasing the forward conduction path of the transistor near its breakdown condition;
• and
• the time constant of said recharging circuit being at least many times greater than the time constant of said discharge circuit, so that when current is being discharged from said capacitor into said inductor through said forward conduction path of said transistor the avalanche mode current carriers will recombine concurrently with or soon after the generation of the RF cycle or cycles, and then end the low resistance avalanche mode.

An electrical circuit for generating and transmitting very short and widely separated high frequency sine-wave pulses of electrical energy, comprising:

• a transistor of the N-P-N type having a base, a collector, and emitter, and a forward conduction path extending from its collector to its emitter;
• a discharge circuit including a delay line and an inductor connected in a first series loop with said forward conduction path of said transistor, said inductor being connected to said emitter;
• a triggering circuit including a coupling capacitor connected to said base of said transistor to provide an input for triggering it into its breakdown or avalanche mode;
• an antenna connected in parallel with said inductor for transmitting electromagnetic energy into space;
• a recharging circuit including a charging resistor and a bias voltage source coupled with said delay line into a second series loop, said bias voltage source being capable of biasing the forward conduction path of the transistor near its breakdown condition;
• and
• the time constant of said recharging circuit being at least many times greater than the time constant of said discharge circuit, so that when current is being discharged from said delay line into said inductor through said forward conduction path of said transistor the avalanche mode current carriers will recombine and end the low resistance avalanche mode upon exhaustion of the charge stored in the charge line.

An electrical circuit utilizing a transistor in the avalanche mode for generating and transmitting very short and widely separated high frequency sine-wave pulses of electrical energy, comprising:

• a discharge circuit including a charging capacitor and an inductor connected in a first series loop, with two electrodes of the transistor forming its forward conduction path;
• a triggering circuit including a coupling capacitor connected to the other electrode of the transistor to provide an input for triggering it into its breakdown or avalanche mode;
• antenna means coupled to said inductor for transmitting electromagnetic energy into space;
• a recharging circuit including a bias voltage source coupled with said charging capacitor into a second series loop, said bias voltage source being capable of biasing the forward conduction path of the transistor near its breakdown condition;
• and
• said recharging circuit being inoperable for recharging said charging capacitor at least until sufficient current has been discharged from said capacitor into said inductor through said forward conduction path of said transistor to cause the avalanche mode current carriers to recombine so as to end the low resistance avalanche mode.

The method of generating and transmitting very short and widely separated high frequency sine-wave pulses of electrical energy, comprising:

• coupling a transistor, a charging capacitor, and a load device into a first series loop path forming a discharge circuit;
• coupling a bias voltage source and the same charging capacitor into a second series loop path forming a recharging circuit with a large RC time constant compared to the first series loop path, the bias voltage source being selected to be capable of biasing the forward conduction path of the transistor near its breakdown condition;
• coupling an antenna means to the load device for transmitting electromagnetic energy pulses into space;
• sampling an original information signal upon each occurrence of a periodic reference signal;
• and
• in response to the signal samples, triggering the transistor into its breakdown or avalanche mode so as to create a series of successive transmitted pulses whose starting times are modified in accordance with the value of the original information signal upon each occurrence of the periodic reference signal.