Abstract:
A gain switching circuit (3) that switches a conversion gain of a preamp (2), which outputs a voltage signal upon amplifying an output current of a photo-detecting element (1) that converts a burst-form optical signal into an electrical signal and with which a series circuit, formed with a first resistor (6) and a first switching element (9), and a series circuit, formed with a second resistor (7) and a second switching element (10), are connected in parallel to a feedback resistor (2B), generates an operating signal for closing the first switching element (9) within a first gain switching period and generates an operating signal for closing the second switching element (10) within a second gain switching period.
Abstract:
An amplifier having programmable operational characteristics and a serial communications interface is fabricated on an integrated circuit (IC). The serial communications interface controls the operational characteristics, e.g., gain, frequency response, etc., of the amplifier. A multiplexer (MUX) may also be included on the IC and may be controlled by the serial communications interface. Status of the amplifier may also be obtained through the serial communications interface. The pin count of the IC package may be kept to a minimum by using the serial communications interface.
Abstract:
The invention provides an automatic gain control and antenna selection method used in a receiver of a radio communication system. The received signal power is estimated by digital signal processing after analog-to-digital conversion in the system, in order to adjust the gain of the front end analog signal until the magnitude of the analog signal is adjusted to an optimum range of the digital signal processing. In addition, the ADC is utilized to estimate the signal power as the basis of the antenna selection.
Abstract:
A programmable gain amplifier (PGA) controlled through a serial communications interface are fabricated on an integrated circuit (IC). A multiplexer (MUX) may also be included on the IC. The serial communications interface controls the gain of the PGA, MUX channel selection, and other functions of the PGA. Status of the PGA may also be obtained through the serial communications interface. By using a serial communications interface, the pin count of the PGA IC package may be kept to a minimum.
Abstract:
An amplifier assembly (100) includes an amplifier (102) having an input terminal, an output terminal and a feedback terminal; a first feedback path connecting the output terminal to the feedback terminal; a second feedback path connecting the output terminal to the feedback terminal; a switch (124) positioned in the second feedback path, the switch (124) opening or closing in response to a voltage at the output terminal relative to a breakpoint, when the switch (124) is open, the amplifier assembly (100) has a first gain and when the switch (124) is closed, the amplifier assembly (100) has a second gain; and a thermally variable element (152) connected to the switch (124), the thermally variable element (152) configured to generate a compensation voltage to maintain the breakpoint in response to varying temperature of the switch (152).
Abstract:
A gain switching circuit switches a conversion gain of a preamplifier that is configured with a series circuit formed with a first resistor and a first switching element and a series circuit formed with a second resistor and a second switching element respectively connected in parallel with a feedback resistor. The gain switching circuit includes a first operating unit that generates a first switching element operating signal for closing the first switching element within a first gain switching period, and a second operating unit that generates a second switching element operating signal for closing the second switching element within a second gain switching period.
Abstract:
Disclosed is a method for controlling power level of received signal in an ultra wide band transmission system which uses multi frequency bands, and includes a pre-gain controller (PGC) and a voltage gain amplifier (VGA). The method for controlling a power level of a received signal includes the steps of: a) at the PGCs, detecting which multi frequency band is used in a transmitter of the transmission system; b) at the PGCs, obtaining the voltage gain owing to the discrepancy in the power levels of the received signals; and c) at the PGCs, compensating for the power loss based on the voltage gain.