摘要:
The present invention provides a modulation circuit that has excellent modulation characteristics and can be designed as an MMIC. Consequently, this modulation circuit is such that the modulating wave input means is composed of a capacitor 21 and an inductor 22, the carrier input means is composed of a capacitor 23 and a resistance element 24, the self-bias means is composed of a resistance element 26 and a capacitor 27, the carrier selection means is composed of an inductor 22 and a capacitor 28, and the modulated wave output means is composed of a capacitor 28.
摘要:
A method is performed for influencing the signal shape of an output signal of an RF power resonance amplifier and an RF excitation arrangement including an RF power resonance amplifier. A basic signal of a basic frequency is amplified and modulated with a modulation signal, and an output oscillating circuit of the RF power resonance amplifier is tuned to a frequency in the range of the basic frequency, and is excited with the basic signal during normal operation. At times that are or can be predetermined, the output oscillating circuit is driven with a driving signal that differs from the basic signal, for a time period that is or can be predetermined. This reduces the dying down time of the output oscillating circuit and increases the steepness of the output signal edges.
摘要:
An amplitude modulator using an FET, or MOSFET and a coupling and phase splitting device capable of accepting both single ended and balanced inputs (like for example, a differential amplifier or a center tapped choke coil, or a transformer). The source and drain terminals are connected to the differential inputs (outputs) of the device, and the signal to the single ended input of the device. The carrier is applied to the gate terminal of the FET or MOSFET. The switching action of the device is equally efficient for both single ended and differential inputs (outputs). However, the carrier leak voltage is being applied simultaneously to both terminals of the differential input and thus suppressed in the output by virtue of high suppression of longitudinal (common) mode pertinent to devices with differential inputs (outputs). Other modulators are disclosed including a double balanced modulator using two complimentary field effect transistors and a double balanced modulator using two field effect transistors of the same conductivity type.
摘要:
Amplitude modulator comprising a differential input pair receiving a modulating input signal, and a Gilbert cell multiplying a carrier signal by the modulating input signal; anda second differential pair of transistors receiving the carrier signal, and the output signal of which is added to the output signal of the Gilbert cell.
摘要:
An amplitude modulator, which has a combining circuit for combining a carrier wave with a power modulating signal to control the amplitude of an output wave of carrier frequency in accordance with the power modulating signal, is very efficient and has low distortion. The power modulating signal is produced by two transistors, one of which is energized by a low DC power supply voltage and the other by a high DC power supply voltage. The lower-voltage transistor alone performs the modulation when an input modulation signal voltage is in the lower-voltage half of its range, and the higher-voltage transistor alone operates to perform the modulation when the input modulation signal is in the higher-voltage half. Neither transistor dissipates much power when the input modulation signal voltage is in the center of its operating range or when the other transistor is active to perform the modulation.
摘要:
An amplitude modulator capable of 100% modulation with low modulation distortion, adaptable to all practical amplitude modulation requirements from D.C. to 120 MHz. The circuit has a differential amplifier with an R.F. input and a bias current from an ultra-linear, voltage-tuned constant current source which is transistor controlled. The differential amplifier provides full limiting of the R.F. input and is biased with a current source comprised of an operational amplifier with its feedback connected to include the bias current controlling transistor.