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| Number | Title | Issue Date |
| 7382208 | Operating method for the resonant operation of high-pressure lamps in longitudinal mode, and an associated system and electronic ballast The operating method is based on the simultaneous application of FM and AM. In this process, the fundamental frequency of the AM is derived from at least one, preferably the second, longitudinal mode. In continuous operation of the lamp, the color temperature is set... | 06/03/2008 |
| 6983024 | Quadra-polar modulator A quadra-polar modulator that is simple to implement and also provides good noise performance. The quadra-polar modulator includes four amplitude modulators and a combiner. Each amplitude modulator modulates a respective carrier signal with a respective input signal... | 01/03/2006 |
| 6208217 | Ask modulator with frequency dependent voltage divider An ASK modulator including a switching diode connected in series to a carrier signal transmitting path, a first resistor connected between one end of the switching diode and a digital signal input end and a second resistor connected between one end of the... | 03/27/2001 |
| 5798674 | Band Limited AM modulator using linear power amplification A band limited Amplitude Shift Keyed (ASK) modulator employing linear modulation and an efficient Class C power amplifier. Band-limited operation is provided by filtering a digital baseband input signal prior to modulation. Closed loop feedback is employe... | 08/25/1998 |
| 5509011 | Transmission system for time-division multiplex signal transmission A time-division multiplex signal transmission system includes a transmitter having a power amplifier with a control input to which is supplied a control voltage (Uc). The power of the amplifier high-frequency output signal (RFout) is... | 04/16/1996 |
| 5222104 | Gain control circuit for radio transmitter A gain control circuit for a radio transmitter, such as the radio transmitter portion of a radiotelephone operative to transmit a π/4 DQPSK-modulated signal in discrete bursts. The signal portion of the signal transmitted during each discrete burst forms... | 06/22/1993 |
| 4816779 | Amplitude stabilized oscillator having positive and negative feedback An oscillator circuit which includes a differential amplifier in combination with a negative feedback network and a positive feedback network connected to the amplifier. One of these networks determines the frequency of the generated oscillation. In order... | 03/28/1989 |
| 4698603 | RF amplitude modulator/mixer A method and apparatus are disclosed for offsetting the DC level of a modulating signal input to a dual balanced modulator. The circuit is adapted to offset a high frequency modulation signal by an amount sufficient to provide the optimum percent modulati... | 10/06/1987 |
| 4654607 | Modulation control circuit for an amplitude modulator An amplitude modulator having first and second differential amplifiers which are commonly supplied with an amplitude modulated carrier signal and a third differential amplifier which is connected to the emitter current path of the first differential ampli... | 03/31/1987 |
| 4520328 | Amplitude modulation circuit having stable modulation characteristics An amplitude modulation circuit wherein a resonant circuit for the determination of the carrier-wave frequency is connected to the collector of one transistor forming a differential pair of transistors forming a differential amplifier having its ground te... | 05/28/1985 |
| 4314374 | High power audio frequency transmitter A high power amplitude modulated audio frequency transmitter having a Twin-T low frequency oscillator, a tickler coil high frequency oscillator, a switching regulator and a switching amplifier. The Twin-T low frequency oscillator produces a sine wave modu... | 02/02/1982 |
| 4247948 | Automatic modulation control in transmitter An automatic modulation control in a transmitter, comprising an alternating modulation signal source, a modulation signal amplifier, a carrier generator, a modulator for modulating the carrier signal as a function of the output of the modulation signal am... | 01/27/1981 |
| 4199723 | Automatic modulation control apparatus The present invention concerns circuitry for comparing the output power of an amplitude modulated RF transmitter with the supply power to the RF transmitter and using feedback from a comparator to a variable gain modulation amplifier to maintain the level... | 04/22/1980 |
| 4122415 | AM transmitter with an offset voltage to the RF stage to compensate for switching time of the modulators An AM transmitter of the type including apparatus for generating a subcarrier signal, pulse width modulating this subcarrier with audio, amplifying this resulting pulse width signal using active devices operating in the more efficient switching mode is di... | 10/24/1978 |
| 4044308 | Communication transmitting apparatus with carrier level control Low level amplitude modulated radio transmitting apparatus employing a DC control loop from the output amplifier to the audio modulating stage for maintaining the carrier output level constant. The audio signal to be transmitted is superimposed on the DC ... | 08/23/1977 |
| 3974460 | High frequency modulator, such as an amplitude modulator, including a frequency multiplier A high-frequency modulator circuit including a frequency multiplier comprised of a first differential amplifier for receiving a base oscillating signal and for multiplying the frequency of the base oscillating signal to thereby produce a higher frequency ... | 08/10/1976 |
| 3965443 | Electronic modulator for guidance systems An amplitude modulation system having a modulation control circuit including a limiter for the modulation signal, a detector for deriving a DC contr0l signal from the unmodulated carrier, a first adjustable network connected to the detector to produce a s... | 06/22/1976 |
