Did You Know...
...that when IBM conducted a market study of Chester Carlson's invention in 1959, the company concluded that it would take only 5000 units of his new product to saturate the market? IBM therefore declined to be part of the new product introduction. Too bad for IBM. Carlson's invention was the xerography process, and his new product was the beginning of the Xerox Corporation. It is estimated that every day, worldwide, 3,000,000,000 copies are made!!
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| Number | Title | Issue Date |
| 7190935 | Amplifier power detection circuitry The present invention provides an efficient way to detect the transmit power provided by an amplifier. A power sense signal indicative of the transmit power of the amplifier is generated and fed back to a control system, which will react accordingly to control input... | 03/13/2007 |
| 7164310 | Systems and apparatus for digital control of bias for transistors The present invention is directed toward a system and apparatus for digitally controlling a bias control signal for at least one transistor. The present invention provides for software writable registers that control the bias control signal. The present invention fu... | 01/16/2007 |
| 7149487 | Mobile communication terminal device and variable gain circuit In receiver systems for cellular phones using the W-CDMA method, the change in DC voltage occurring when the gain of a programmable gain amplifier (PGA circuit) is switched to adjust the gain for a received signal, can be suppressed. A sample-and-hold circuit is ins... | 12/12/2006 |
| 7133346 | Photo-detector amplifier circuit for optical disk device A two-stage amplifier of a first-stage amplifier 21 and second-stage amplifiers 22 and 23 is provided. A writing mode and reproducing modes are switched in the first-stage amplifier 21 by switching a parallel circuit of a feedback capacit... | 11/07/2006 |
| 7123089 | Power amplifier with pulse differentiating circuit An amplifier includes a plurality of power amplifier elements connected in cascaded multiple stages, a first bias power supply, a second bias power supply, a switching circuit configured to switch a first output supplied from the first bias power supply in response ... | 10/17/2006 |
| 7068100 | Gain control methods and systems in an amplifier assembly A Variable Gain Amplifier (VGA) amplifies an input signal according to a gain, to produce an amplified signal. A detector module detects a power indicative of a power of the amplified signal. A comparator module compares the detected power to a high threshold, a low... | 06/27/2006 |
| 6930553 | Automatic gain control device and automatic gain control method An automatic gain control device comprises a variable gain amplifier (VGA) for increasing the amplitude of an input analog signal that has a plurality of CAPA having different signal characteristics; an A/D converter for sampling the output from the VGA to convert i... | 08/16/2005 |
| 6750708 | Miniaturized buffer amplifier and electronic circuit unit using same A buffer amplifier is provided which includes an amplifying transistor, an inductance element for feeding power to the collector of the amplifying transistor from a power supply, a resistance attenuator having an input end, an output end, and a ground end, and an ou... | 06/15/2004 |
| 6608524 | Automatic gain control circuit In a state where a PLL circuit is not locked, a gain control signal according to the difference between a peak value of a reproduced signal and the upper or lower limit value of the dynamic range of an A/D converter is given to a variable gain amplifier. ... | 08/19/2003 |
| 6570443 | Amplitude control of an alternating signal generated by an electronic device such as an oscillator circuit There is described an amplitude-controlled electronic device (1) intended to generate at an output (11; 11a) an alternating output signal (S1; Sosc) of substantially constant amplitude. This electronic device includes a measuring branch (20; 20*; 201) for... | 05/27/2003 |
| 6087901 | Tuning amplifier A tuning amplifier 1 is provided with an oscillation circuit 10 incorporating an amplifier circuit 11 and a feedback circuit 12, an input circuit 14 which inputs signals to the oscillation circuit 10, and an automatic gain control (AGC) circuit 16 which c... | 07/11/2000 |
| 5963087 | Gain control circuit and method for providing gain control of a variable amplifier using a pilot signal The present invention provides for a gain control circuit (10) and method for providing gain control of a variable amplification circuit (16) using a pilot signal. A pilot signal is added to the received signal. The pilot signal has at least a minimum sig... | 10/05/1999 |
| 5960333 | Circuitry and method for power calibration A method and circuitry for improved output power level calibration/compensation/control is disclosed. A single RF detector diode is employed, to which a bias current is applied prior to applying a coupled amount of the transmitted radio frequency signal t... | 09/28/1999 |
| 5874860 | High frequency amplifier and control A monolithic RF amplifier circuit (10) suitable for use in the 0.8-2 GHz frequency range comprises, on-chip (12'), a gateable oscillator (24) running at about 2-5 times the amplifier input frequency or higher, coupled to a rectifier (30) and a low pass fi... | 02/23/1999 |
| 5784689 | Output control circuit for transmission power amplifying circuit A higher output of two outputs from a trapezoidal wave generating circuit 4 and a pulse generating circuit 5 is produced. The control voltage signal is formed by combining the trapezoidal wave signal and the pulse signal. Sharp rising and falling edges of... | 07/21/1998 |
| 5714908 | Power correction method and circuit An amplifier amplifies a signal derived from the output of a voltage-controlled oscillator. The frequency control voltage applied to the voltage-controlled oscillator is also applied, after suitable level conversion, to the amplifier as a gain control sig... | 02/03/1998 |
| 5327583 | Using a clock signal generated by a microcomputer for providing a negative bias voltage to a galium arsenide field effect transistor in a high frequency amplifier of the device In a mobile radio communication device, a gain of a GaAs FET for high frequency power amplification is controlled by a negative voltage based on a clock signal generated by a microcomputer in the device.... | 07/05/1994 |
| 5196806 | Output level control circuit for use in RF power amplifier An output level control circuit for a high frequency power amplifier for amplifying high frequency signals having the "on" and "off" periods of transmit signals in a fixed recurrent cycle such as in a TDMA radio communication system or a GSM system. The h... | 03/23/1993 |
| 5194823 | Modulation means for an RF power amplifier Modulation device for an RF power amplifier. A correction of the modulation pulse is defined from the non-linear control characteristic of the RF power amplifier (2) such that the influence on the desired output pulse shape caused by the non-linear contro... | 03/16/1993 |
| 5175749 | Apparatus and method for DC offset correction in a receiver An apparatus automatically corrects for DC offset in a multi-level packet-switched receiver. A reference carrier frequency is used during the receiver's idle mode to establish a DC offset exiting a discriminator (302). The DC offset is amplified by a vide... | 12/29/1992 |
| 4996500 | Automatic control system An automatic power control system compensates for temperature variable components in a broadband signal generator by providing a reference signal generating circuit that is temperature matched with an automatic level control feedback circuit. The temperat... | 02/26/1991 |
| 4994757 | Efficiency improvement of power amplifiers Circuitry changes the magnitude of power supply voltages to correspond to the desired level of a variable output power. This maximizes the electrical power efficiency of amplifiers. The circuitry also provides for automatic control of the amplitude of the... | 02/19/1991 |
| 4873492 | Amplifier with modulated resistor gain control An automatic gain control circuit for an amplifier operating over a prescribed frequency range detects the output level of the amplifier; and couples a repeated predetermined waveform occurring at a rate greater than the reciprocal of twice the upper freq... | 10/10/1989 |
| 4670719 | Digitally processing automatic gain control circuit An automatic gain control circuit includes a gain controllable amplifier, a sampling circuit sampling the output of the amplifier, a rewritable memory storing a contrast digital value, an analog/digital converter converting the sampled signal into a digit... | 06/02/1987 |
| 4591809 | High frequency power source A power source consisting of a low power high frequency oscillator section driving a high power high gain amplifier section. The amplifier section includes one or more SIT's. The dc operating potential is applied to the drain electrode of one of the SIT's... | 05/27/1986 |
| 4570127 | Automatic gain control circuit for burst signal communication system An AGC circuit for amplifying burst signals has output power which does not vary, regardless of variations in the burst time. This automatic gain control (AGC) circuit has an amplifier for receiving a burst signal input and providing an amplified burst ou... | 02/11/1986 |
| 4514701 | Automatic level control circuit An amplitude control circuit of the invention includes a vector composition circuit (18) for composing a cosine-wave signal (e3) from a sine-wave signal (e1) and a control signal generation circuit (20) for providing a control signal (e4) from the sine- a... | 04/30/1985 |
| 4350962 | R.F. switched amplifier and A.M. modulator An amplifier circuit incorporating a valve or vacuum tube in the grounded grid configuration is disclosed. The anode D.C. potential is greater than the cathode D.C. potential which is in turn greater than the grid D.C. potential. The cathode is switched a... | 09/21/1982 |
| 4194164 | Variable frequency sources An R.F. signal generator is arranged to provide an output signal having a controlled level, by means of a feedback loop into which an additional frequency dependent control signal is injected. This additional control signal is derived from a resistor netw... | 03/18/1980 |
