Patent application number | Description | Published |
20130257462 | PACKAGE STRUCTURE WITH CONFORMAL SHIELDING AND INSPECTION METHOD USING THE SAME - A package structure with conformal shielding includes a substrate providing electrically connected inner grounding structures, a chip module mounted on the substrate, a molding compound covering the chip module and one surface of the substrate, and a conductive shielding layer covering the molding compound and the lateral sides of the substrate, and electrically connected with a part of the inner grounding structures. The substrate further provides one or multiple independent conductive structures electrically connected with the conductive shielding layer and exposed to the outside. By measuring the resistance value between one independent conductive structure and the conductive shielding layer or another independent conductive structure or one ground contact and then comparing the measured resistance value with a predetermined reference value, the EMI shielding performance of the package structure is determined. | 10-03-2013 |
20140132350 | ELECTRONIC SYSTEM, RF POWER AMPLIFIER AND TEMPERATURE COMPENSATION METHOD THEREOF - A radio frequency (RF) power amplifier is disclosed. The RF radio power amplifier includes a bias current generating unit, a first impedance unit, a second impedance unit, a third impedance unit and an output stage unit. The bias current generating unit receives a reference voltage. There is a first voltage with negative temperature coefficient between the first impedance unit and the second impedance unit, and the second unit receives a ground current. There is a second voltage between the third impedance unit and the second impedance unit, and the second voltage is a partial voltage of the first voltage. The bias current generating unit outputs a bias current with positive temperature coefficient according to the second voltage. The output stage unit receives an input current. The bias current is a sum of the input current with positive temperature coefficient and the ground current. | 05-15-2014 |
20140153670 | ELECTRONIC SYSTEM, RF POWER AMPLIFIER AND TEMPERATURE COMPENSATION METHOD THEREOF - A radio frequency (RF) power amplifier is disclosed. The RF power amplifier includes an adder circuit, an output-stage circuit and a differential circuit. The adder circuit has a first ratio and a second ratio, and receives a reference voltage and a feedback voltage so as to output an adder voltage after an operation, wherein the feedback voltage is a voltage with a negative temperature coefficient, and the reference voltage is sum of a first voltage with a negative temperature coefficient and a second voltage with positive temperature coefficient. The output-stage circuit is used for providing the feedback voltage. The differential circuit has a first multiplier factor, and the differential circuit makes the first multiplier factor be multiplied with the adder voltage so as to provide a voltage to the output-stage circuit. The RF power amplifier stabilizes an output current through adjusting the temperature coefficient of the reference voltage. | 06-05-2014 |
20140159819 | ELECTRONIC SYSTEM, RF POWER AMPLIFIER AND OUTPUT POWER COMPENSATION METHOD THEREOF - A radio frequency (RF) power amplifier is disclosed. The power amplifier includes an output stage circuit, an exponential type bias circuit and a voltage-current transformation circuit. The output stage circuit receives a first system voltage and outputs an output current. The exponential type bias circuit receives a bias current, wherein a relationship between the bias current and output current is exponential, and when the bias current is zero current, and the output current is zero current. The voltage-current transformation circuit transforms the first system voltage into a second current so that the bias current is in proportion to the first system voltage, and thus the relationship between the output current and the first system voltage is exponential. The bias current is equal to times of the sum of the first current and the second current. | 06-12-2014 |
20140167854 | ELECTRONIC SYSTEM - RADIO FREQUENCY POWER AMPLIFIER AND METHOD FOR SELF-ADJUSTING BIAS POINT - A radio frequency (RF) power amplifier is disclosed. The RF power amplifier includes a bias circuit, an output stage circuit and dynamic bias controlling circuit. The bias circuit receives a system voltage and the bias circuit provides a working voltage according to the system voltage. The output stage circuit receives the working voltage so as to work at an operation bias point. The dynamic bias controlling circuit receives the working voltage and outputs a compensation voltage to the bias circuit according to a variation of the working voltage. When the input power increases and makes the working voltage decreases so as to shift the operation bias point, the bias circuit adjusts the working voltage upward so as to recover the operation bias point according to the compensation voltage received. | 06-19-2014 |
20140327482 | RADIO FREQUENCY POWER AMPLIFIER WITH NO REFERENCE VOLTAGE FOR BIASING AND ELECTRONIC SYSTEM - A radio frequency (RF) power amplifier with no reference voltage for biasing is disclosed. The RF power amplifier includes a three-terminal current source circuit, a current mirror circuit and an output-stage circuit. The three-terminal current source circuit receives a first system voltage and accordingly outputs a first current and a second current, and a source voltage exists between a first output terminal of the first current and a second output terminal of the second current. The current mirror circuit receives the first current and the second current and accordingly generates a bias current. The output-stage circuit receives the bias current so as to work at an operation point. The RF power amplifier utilizes the source voltage of the three-terminal current source circuit so the first system voltage is between a first voltage and a second voltage, and then the output-stage circuit outputs an output current which does not vary with a deviation of the first system voltage also with temperature compensation. | 11-06-2014 |
20140354259 | BANDGAP REFERENCE VOLTAGE GENERATING CIRCUIT AND ELECTRONIC SYSTEM USING THE SAME - A bandgap reference voltage generating circuit for providing a reference voltage is disclosed. The bandgap reference voltage generating circuit includes four-terminal current source circuit, a regulator circuit and a temperature-compensating circuit. The four-terminal current source circuit outputs a first voltage, a second voltage and a first current which are independent of variation of a first system voltage. The regulator circuit receives the first voltage and the second voltage and when the first system voltage is larger than a threshold voltage value, the regulator circuit outputs the reference voltage independent of variation of the first system voltage via voltage-difference between the first voltage and the second voltage. The temperature-compensating circuit receives the first current and compensates a temperature curve of the reference voltage outputted from the regulator circuit. | 12-04-2014 |
20140368277 | RADIO FREQUENCY POWER AMPLIFIER AND ELECTRONIC SYSTEM - A radio frequency (RF) amplifier is disclosed. The RF power amplifier includes a bias circuit, an output-stage circuit and a RF compensation circuit. When a first system voltage is larger than a first voltage threshold value, the bias circuit generates a first current rising slightly. When first system voltage is larger than second voltage threshold value, the RF compensation circuit receives a second circuit rising slightly transmitted from the bias circuit. When the first system voltage is in an operation voltage range, the first current is larger than the second circuit so as to a quiescent operating current of the RF power amplifier is independent of change of the first system voltage. When the first system voltage is larger than a third voltage threshold value, the first current is equal to the second current so as to have the bias current being a zero current to protect the RF power amplifier from over-voltage. | 12-18-2014 |