Abstract: An apparatus includes a radio frequency (RF) input port, an RF output port, a variable attenuation network, a first filter network, a second filter network, and a third filter network. The variable attenuation network may be coupled between the RF input port and the RF output port. Attenuation of the variable attenuation network is controlled by a first control signal and a second control signal. The first filter network may be connected between the RF input port and the RF output port. The second filter network may be connected between the variable attenuation network and a ground potential. The third filter network may be connected between the variable attenuation network and the ground potential. The first, the second, and the third filter networks modify performance of the variable attenuation network to produce a particular tilt of a radio frequency signal passing through the apparatus between the RF input port and the RF output port.

Abstract: An apparatus includes a radio frequency (RF) input port, an RF output port, a variable attenuation network, a first filter network, a second filter network, and a third filter network. The variable attenuation network may be coupled between the RF input port and the RF output port. Attenuation of the variable attenuation network is controlled by a first control signal and a second control signal. The first filter network may be connected between the RF input port and the RF output port. The second filter network may be connected between the variable attenuation network and a ground potential. The third filter network may be connected between the variable attenuation network and the ground potential. The first, the second, and the third filter networks modify performance of the variable attenuation network to produce a particular tilt of a radio frequency signal passing through the apparatus between the RF input port and the RF output port.

Abstract: An apparatus having a first circuit and a second circuit. The first circuit may be configured to generate an output signal in response to an intermediate signal. The first circuit may be implemented using a first transistor type. The second circuit may be configured to generate the intermediate signal in response to (i) an input signal and (ii) a feedback of the output signal. The second circuit may be implemented using a second transistor type. The output signal is an amplified version of the input signal while maintaining linearity.

Abstract: An apparatus having a first circuit and a second circuit. The first circuit may be configured to generate an output signal in response to an intermediate signal. The first circuit may be implemented using a first transistor type. The second circuit may be configured to generate the intermediate signal in response to (i) an input signal and (ii) a feedback of the output signal. The second circuit may be implemented using a second transistor type. The output signal is an amplified version of the input signal while maintaining linearity.

Abstract: A dual band mixer has a common node for at least one radio frequency input and an intermediate frequency output. The dual band mixer also has a first transistor with a gate coupled to a first local oscillator input and a drain coupled to the common node, and a second transistor with a gate coupled to a second local oscillator input and a drain coupled to the common node. Interconnection circuitry turns off the second transistor when the first local oscillator input signal is applied to the first transistor, and turns off the first transistor when the second local oscillator input signal is applied to the second transistor.

Abstract: A hand-held computing device including a pair of grouped buttons disposed in a pattern including at least one row, such that each input device in each row is substantially equidistant from a location or point unique to each group is used to optimize the use of the user's thumbs for data input. The use of the thumb is the most powerful digit on the hand and has the greatest range of motion. Using only the thumbs to actuate the buttons of computing device such as a calculator, allows the hand to remain less obtrusive to the accessing the buttons, therefore less prone to input errors. In addition, by maintaining the relative position of the rest of the hand at a consistent location on the housing, the user's proprioceptive and kinesthetic senses allow the user to learn and consistently locate keys. Upon this learning, the user would be able to input data without visual cues further increasing efficiency with a short learning curve.

Abstract: A dual band mixer has a common node for at least one radio frequency input and an intermediate frequency output. The dual band mixer also has a first transistor with a gate coupled to a first local oscillator input and a drain coupled to the common node, and a second transistor with a gate coupled to a second local oscillator input and a drain coupled to the common node. Interconnection circuitry turns off the second transistor when the first local oscillator input signal is applied to the first transistor, and turns off the first transistor when the second local oscillator input signal is applied to the second transistor.

Abstract: A dual band mixer has a common node for at least one radio frequency input and an intermediate frequency output. The dual band mixer also has a first transistor with a gate coupled to a first local oscillator input and a drain coupled to the common node, and a second transistor with a gate coupled to a second local oscillator input and a drain coupled to the common node. Interconnection circuitry turns off the second transistor when the first local oscillator input signal is applied to the first transistor, and turns off the first transistor when the second local oscillator input signal is applied to the second transistor.

Abstract: In one aspect, a bias circuit includes a rectifier, a negative bias level setter, and a negative bias extractor. The rectifier has a rectifier input and a rectifier output. The rectifier is configured to produce at the rectifier output a negative rectified voltage signal from an alternating input signal applied at the rectifier input. The negative bias level setter couples to the rectifier output and provides a path for current establishing the negative rectified voltage signal produced at the rectifier output. The negative bias extractor has an extractor output and an extractor input coupled to the rectifier output. The negative bias extractor is configured to produce at the extractor output a substantially constant negative bias signal from the negative rectified voltage signal produced at the rectifier output.

Abstract: Mixer circuitry having a semiconductor body formed therein mixer circuitry having an oscillator having a heterojunction bipolar transistor and a mixer having a Schottky diode. The heterojunction transistor has a collector region formed in one portion of doped layer of the semiconductor body and the diode has a metal electrode is Schottky contact with another portion of such doped layer. The mixer is includes a diode and a DC biasing circuit, comprising a constant current, for biasing such diode to predetermined operating point substantially invariant with power of an input signal fed to such mixer.

Abstract: Mixer circuitry having a semiconductor body formed therein mixer circuitry having an oscillator having a heterojunction bipolar transistor and a mixer having a Schottky diode. The heterojunction transistor has a collector region formed in one portion of doped layer of the semiconductor body and the diode has a metal electrode is Schottky contact with another portion of such doped layer. The mixer is includes a diode and a DC biasing circuit, comprising a constant current, for biasing such diode to predetermined operating point substantially invariant with power of an input signal fed to such mixer.

Abstract: Mixer circuitry having a semiconductor body formed therein mixer circuitry having an oscillator having a heterojunction bipolar transistor and a mixer having a Schottky diode. The heterojunction transistor has a collector region formed in one portion of doped layer of the semiconductor body and the diode has a metal electrode is Schottky contact with another portion of such doped layer. The mixer is includes a diode and a DC biasing circuit, comprising a constant current, for biasing such diode to predetermined operating point substantially invariant with power of an input signal fed to such mixer.