Abstract: An electronic device includes a shared pin and a bandwidth extension circuit. The electronic device receives or transmits a signal through the shared pin. The bandwidth extension circuit is electrically coupled to the shared pin. The bandwidth extension circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor. The first inductor is electrically connected between the shared pin and a node. The second inductor is electrically connected to the first inductor through the node. The first capacitor is electrically connected between the node and a ground. The second capacitor is electrically connected between the shared pin and the ground. The third capacitor is electrically connected between the second inductor and the ground. The first inductor is different from the second inductor. There is no coupling effect between the first inductor and the second inductor.

Abstract: A method and an optical transmitter utilizing the same are provided. The method, adopted by an optical transmitter, transmitting data signal and control signal to an optical receiver of an target device, including: providing a data signal in a first frequency band; providing a control signal in a second frequency band; combining the data signal in the first frequency band and the control signal in the second frequency band to generate a combined signal; and converting the combined signal into an outgoing optical signal to be transmitted to the optical receiver; wherein the control signal is arranged for controlling the target device.

Abstract: A power amplifier amplifying an input signal is provided, comprising a power amplifier circuit, a bias circuit, and a compensation circuit. The power amplifier circuit has an input impedance responsive to the input signal, and amplifies the input signal to generate an output signal. The bias circuit is coupled to the power amplifier circuit, generates a DC bias signal to the power amplifier so that the power amplifier amplifies the input signal. The compensation circuit is coupled to the power amplifier circuit, provides a compensation impedance responsive to the input signal such that a combination of the input impedance and the compensation impedance is substantially constant regardless of the input signal.

Abstract: A harmonic-rejection modulation device is provided, which includes a phase splitter, a low pass filter, and a modulator. Based on a square wave, the phase splitter generates a plurality of unfiltered local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The low pass filter filters the high frequency components of the unfiltered local oscillating signals to generate a plurality of local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The modulator modulates a baseband signal with the local oscillating signals, wherein the third harmonics of the local oscillating signals are eliminated by the modulation process of the modulator. The invention also provides a method of modulating a baseband signal.

Abstract: A multimode communications system includes a first communications module, a transmission module, a switch and a second communications module. The first communication module has a frequency modulator for modulating a dividing ratio to adjust an oscillating signal and selectively enabling the oscillating signal to have its frequency change with a variety of contents of a first communications signal by modulating the dividing ratio according to the contents of the first communications signal on a modulating mode or enabling the oscillating signal to have its frequency constant by keeping the dividing ratio unchanged. The switch is to selectively transmit the oscillating signal either to the transmission module when the frequency modulator is operating on the modulating mode or to a receiving end when the frequency modulator is operating on the constant frequency mode.

Abstract: A power amplifier amplifying an input signal is provided, comprising a power amplifier circuit, a bias circuit, and a compensation circuit. The power amplifier circuit has an input impedance responsive to the input signal, and amplifies the input signal to generate an output signal. The bias circuit is coupled to the power amplifier circuit, generates a DC bias signal to the power amplifier so that the power amplifier amplifies the input signal. The compensation circuit is coupled to the power amplifier circuit, provides a compensation impedance responsive to the input signal such that a combination of the input impedance and the compensation impedance is substantially constant regardless of the input signal.

Abstract: A wireless communication device. The wireless communication device comprises first and second programmable frequency dividers, a mixer, a modulator, a phase detector, and a variable controlled oscillator. The first programmable frequency divider divides the frequency of a reference signal by a factor N to generate a modulating signal. The second programmable frequency divider divides the reference signal by a factor M and outputs a frequency-divided signal. The facts N and M are positive integers. The mixer down-converting a transmission signal according the divided signal and outputs a translation-loop signal. The modulator modulates the modulating signal with baseband signals, and outputs a comparison signal. The phase detector detects a phase difference between the comparison signal and the translation-loop signal. The variable controlled oscillator modifies the transmission signals according to an output of the phase detector.

Abstract: A power amplifier circuit amplifying an input signal to an output signal and a method thereof. The power amplifier circuit comprises a ramp controller, a current source, and a first amplification stage. The ramp controller receives an enable signal to generate a ramp signal. The current source is coupled to the ramp controller, produces a ramp current by the ramp signal. The first amplification stage is coupled to the current source, comprises a first supply voltage input coupled to a fixed supply voltage, and is biased by the ramp current to amplify the input signal such that an envelope of the output signal is a ramp.

Abstract: A harmonic-rejection modulation device is provided, which includes a phase splitter, a low pass filter, and a modulator. Based on a square wave, the phase splitter generates a plurality of unfiltered local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The low pass filter filters the high frequency components of the unfiltered local oscillating signals to generate a plurality of local oscillating signals having phase angles of 0°, 30°, 90°, 120°, 180°, 210°, 270° and 300°, respectively. The modulator modulates a baseband signal with the local oscillating signals, wherein the third harmonics of the local oscillating signals are eliminated by the modulation process of the modulator. The invention also provides a method of modulating a baseband signal.

Abstract: A radio communication system for communication between a first mobile system and a second mobile system. Each mobile system has a transceiver for receiving and emitting radio signal. The second mobile system comprises a received signal strength detecting device, a power controller and an indicating device. The received signal strength detecting device detects a received signal strength of the transceiver in the second mobile system. The power controller outputs a transmitted power strength status and controls transmitted power of the transceiver according to the received signal strength. The indicating device receives the transmitted power strength status and indicates a transmitted RF power strength status of the transceiver in the second mobile.

Abstract: A power amplifier circuit amplifying an input signal to an output signal and a method thereof. The power amplifier circuit comprises a ramp controller, a current source, and a first amplification stage. The ramp controller receives an enable signal to generate a ramp signal. The current source is coupled to the ramp controller, produces a ramp current by the ramp signal. The first amplification stage is coupled to the current source, comprises a first supply voltage input coupled to a fixed supply voltage, and is biased by the ramp current to amplify the input signal such that an envelope of the output signal is a ramp.

Abstract: A modulating mechanism is provided comprising a first storage and a corresponding first DAC, and a second storage and a corresponding second DAC. The first storage stores an adjusted digital representation of a first waveform, while the second storage stores an adjusted digital representation of a second waveform. The adjusted representation of the first waveform is adjusted to compensate for the deviation effects experienced by the first DAC (e.g. amplitude deviation, DC offset, non-linearity, etc.). The adjusted representation of the second waveform is adjusted to compensate for the deviation effects experienced by the second DAC. In effect, the adjusted representations of the first and second waveforms cause the DAC's to exhibit the proper behavior, despite the presence of the deviation effects. By storing and using adjusted digital representations of waveforms in this manner, many benefits can be realized, including for example, eliminating the need for any analog compensation circuits.

Abstract: A multimode communications system includes a first communications module, a transmission module, a switch and a second communications module. The first communication module has a frequency modulator for modulating a dividing ratio to adjust an oscillating signal and selectively enabling the oscillating signal to have its frequency change with a variety of contents of a first communications signal by modulating the dividing ratio according to the contents of the first communications signal on a modulating mode or enabling the oscillating signal to have its frequency constant by keeping the dividing ratio unchanged. The switch is to selectively transmit the oscillating signal either to the transmission module when the frequency modulator is operating on the modulating mode or to a receiving end when the frequency modulator is operating on the constant frequency mode.

Abstract: The present invention provide a radio communication device having a transmitter for emitting a radio signal to a corresponding receiver comprise an indicating means and a controller; wherein the indicating means for indicating a transmitted RF power strength status of the transmitter; the controller for detecting and outputting the transmitted power strength status to the indicating means, the controller including a power detecting means; wherein the power detecting means coupled to the transmitter for detecting a transmitted power level of the radio signal emitted from a transmitter to a corresponding receiver.

Abstract: A modulating mechanism is provided comprising a first storage and a corresponding first DAC, and a second storage and a corresponding second DAC. The first storage stores an adjusted digital representation of a first waveform, while the second storage stores an adjusted digital representation of a second waveform. The adjusted representation of the first waveform is adjusted to compensate for the deviation effects experienced by the first DAC (e.g. amplitude deviation, DC offset, non-linearity, etc.). The adjusted representation of the second waveform is adjusted to compensate for the deviation effects experienced by the second DAC. In effect, the adjusted representations of the first and second waveforms cause the DAC's to exhibit the proper behavior, despite the presence of the deviation effects. By storing and using adjusted digital representations of waveforms in this manner, many benefits can be realized, including for example, eliminating the need for any analog compensation circuits.

Abstract: A radio communication system for communication between a first mobile system and a second mobile system. Each mobile system has a transceiver for receiving and emitting radio signal. The second mobile system comprises a received signal strength detecting device, a power controller and an indicating device. The received signal strength detecting device detects a received signal strength of the transceiver in the second mobile system. The power controller outputs a transmitted power strength status and controls transmitted power of the transceiver according to the received signal strength. The indicating device receives the transmitted power strength status and indicates a transmitted RF power strength status of the transceiver in the second mobile.

Abstract: A universal multi-band (5 bands or more) RF remote control unit using Bluetooth radio module (a low cost device operating at 2.4 GHz) as the base. It is a keyless, transportable, and low cost unit which can replace most of the conventional individual, in-compatible remote control units with a single universal unit.