Abstract: A filter auto-calibration system includes a multi-clock module. The multi-clock module includes a multi-clock generator that is configured to generate a clock signal with a variable frequency based on a channel setting. There is at least one filter to be calibrated. An auto-calibration control module is configured to control calibration of the at least one filter based on the channel setting. The multi-clock module is configured to supply the variable frequency clock signal to the at least one filter and to the auto-calibration control module, and the at least one filter is coupled to the auto-calibration control module.

Abstract: An RC filter is calibrated to a desired cutoff frequency by initializing the filter with a cutoff frequency. An input signal is filtered by the RC filter to provide a filter output signal having phase and frequency values. The cutoff frequency of the RC filter is adjusted based on the phase and frequency values of the filter output signal if the phase and frequency values do not satisfy a predetermined condition. The filtering and adjusting are repeated until the phase and frequency values of the filter output signal satisfy the predetermined condition. A calibration apparatus has a frequency generator, a resistor-capacitor (RC) filter, a phase comparator, a frequency detector, and a state machine. The phase comparator, frequency detector, and state machine are configured to calibrate the RC filter to a cutoff frequency specified by the reference signal based on a filter output signal of the RC filter.

Abstract: The present invention discloses a bandpass amplifier having gain and bandpass performance. The bandpass amplifier includes an input match unit for matching the gain of the amplifier and having a first filter response; a first bias unit electrically connected to the input match unit for driving the first terminal of the amplifier and having a first high pass filter response; a gain stage electrically connected to the first bias unit for providing the flat gain of the amplifier; a second bias unit electrically connected to the gain stage for driving the second terminal of the amplifier and having a second high pass filter response; and an output match unit electrically connected to the second bias unit for matching the gain of the amplifier and having a second filter response.

Abstract: An apparatus of dual-monitor portable computer and operational method thereof is a portable computer with another sub-monitor which is configured on the lid. The sub-monitor can display different menu for the user to determine which functionality shall execute. The apparatus includes at least CPU, north bridge chipset, south bridge chipset, system memory, a first display monitor, coupling to the north bridge chipset, and a secondary display monitor, the sub-monitor coupling to a keyboard controller and a programmable logic controller. The apparatus also includes BIOS and a or plurality of hotkeys, coupling to the keyboard controller, to assist the user's operation.

Abstract: A dual-band bandpass filter with stepped-impedance resonators uses only one circuit to generate dual-band effect. It adopts the principle of stepped-impedance resonator, which contains a connecting section and two coupling sections. The impedance and electrical length of the connecting section and coupling sections conforms to a selected condition to generate two passbands at desired frequencies. A multi-layer broadside-coupled parallel lines structure may be applied to increase coupling-amount between the parallel lines so that the dual-band bandpass filters have broader bandwidth and less loss.

Abstract: A spurline directional coupler includes a first coupling section and a second coupling section that are in parallel with each other for coupling, and a first sub-coupling section and a second sub-coupling section coupled with the first coupling section, and a third sub-coupling section and a fourth sub-coupling section coupled with the second coupling section. The parallel coupling relationship between the coupling section and the sub-coupling sections generates a capacitive effect thereby may improve isolation and directivity of the spurline directional coupler.

Abstract: An impedance matching circuit for providing a lossless target signal transmission and rejecting image signals of heterodyne and super-heterodyne transceiver. The impedance matching circuit includes a grounded metal membrane, a first microstrip line connected with an input circuit, a second microstrip line connected with an output circuit, and a third microstrip line connected with either the first microstrip line or the second microstrip line. The first microstrip line is not connected with the second microstrip line, and the length of the third microstrip line is equal to a quarter wavelength of an image signal. When the target signal and the image signal transmit to the impedance matching circuit, the image signal will bypass to a grounded metal membrane, and the target signal will transmit to the output circuit without signal decay through electromagnetic coupling of the first microstrip line and the second microstrip line.

Abstract: A low-phase noise oscillator with a microstrip resonator for generating a target signal with a predetermined frequency is provided. The resonator includes a first microstrip line and a second microstrip line. The first microstrip line is parallel with the second microstrip line without having any contact. A length of the first microstrip line equals a length of the second microstrip line, and the length equals a quarter wavelength of the target signal. When a plurality of oscillating signals is transmitted to the first microstrip line, one of the oscillating signals having the predetermined frequency will be output from the resonator by an electromagnetic coupling generated between the first microstrip line and the second microstrip line.

Abstract: A computer remotely controlled turned on or off by a remote controller is provided. The computer includes a receiver, a microprocessor, a power source management module, an I/O controller, a universal output device, and an audio player. The receiver receives a signal from the remote controller. The microprocessor executes a corresponding command according to a frequency of the signal by a pre-configured frequency spectrum table. The I/O controller controls the power source management module according to the command executed by the microprocessor. Thereby, the remote controller can remotely turning on or off the computer, and can perform some specific functions to make the computer much more functionally similar to, the electric appliance.

Abstract: An impedance matching circuit for providing a lossless target signal transmission and rejecting image signals of heterodyne and super-heterodyne transceiver. The impedance matching circuit includes a grounded metal membrane, a first microstrip line connected with an input circuit, a second microstrip line connected with an output circuit, and a third microstrip line connected with either the first microstrip line or the second microstrip line. The first microstrip line is not connected with the second microstrip line, and the length of the third microstrip line is equal to a quarter wavelength of an image signal. When the target signal and the image signal transmit to the impedance matching circuit, the image signal will bypass to a grounded metal membrane, and the target signal will transmit to the output circuit without signal decay through electromagnetic coupling of the first microstrip line and the second microstrip line.

Abstract: A low-phase noise oscillator with a microstrip resonator for generating a target signal with a predetermined frequency is provided. The resonator includes a first microstrip line and a second microstrip line. The first microstrip line is parallel with the second microstrip line without having any contact. A length of the first microstrip line equals a length of the second microstrip line, and the length equals a quarter wavelength of the target signal. When a plurality of oscillating signals is transmitted to the first microstrip line, one of the oscillating signals having the predetermined frequency will be output from the resonator by an electromagnetic coupling generated between the first microstrip line and the second microstrip line.