Abstract: An apparatus for and method of extending the dynamic range of a RF communications receiver. The invention provides a mechanism for controlling the gain of both the LNA and down conversion mixer in the front end portion of an RF receiver. Both the LNA and the mixer are adapted to have both low and high gain modes of operation. The control mechanism typically comprises a two bit gain control that places both the LNA and mixer in one of four operating gain mode states. The selection of the most appropriate operating gain mode state, is preferably determined in accordance with various metrics such as the received levels of the desired signal, levels of interference signals, bit error rate and receiver RSSI.

Abstract: An apparatus for and method of extending the dynamic range of a RF communications receiver. The invention provides a mechanism for controlling the gain of both the LNA and down conversion mixer in the front end portion of an RF receiver. Both the LNA and the mixer are adapted to have both low and high gain modes of operation. The control mechanism typically comprises a two bit gain control that places both the LNA and mixer in one of four operating gain mode states. The selection of the most appropriate operating gain mode state, is preferably determined in accordance with various metrics such as the received levels of the desired signal, levels of interference signals, bit error rate and receiver RSSI.

Abstract: A novel integrated circuit incorporating a transmit/receive antenna switch capable of being integrated using silicon based RF CMOS semiconductor processes and a power amplifier on the same substrate. The switch circuit is constructed whereby the substrate (i.e. bulk) terminals of the FETs are left floating thus improving the isolation and reducing the insertion loss of the switch. Floating the substrate of the transistors eliminates most of the losses caused by leakage paths through parasitic capacitances internal to the transistor thus improving the isolation and reducing the insertion loss of the switch. Alternatively, the substrate can be connected to the source or to ground via a resistor of sufficiently high value to effectively float the substrate.

Abstract: A novel integrated circuit incorporating a transmit/receive antenna switch capable of being integrated using silicon based RF CMOS semiconductor processes and a power amplifier on the same substrate. The switch circuit is constructed whereby the substrate (i.e. bulk) terminals of the FETs are left floating thus improving the isolation and reducing the insertion loss of the switch. Floating the substrate of the transistors eliminates most of the losses caused by leakage paths through parasitic capacitances internal to the transistor thus improving the isolation and reducing the insertion loss of the switch. Alternatively, the substrate can be connected to the source or to ground via a resistor of sufficiently high value to effectively float the substrate.

Abstract: A novel frequency synthesizer incorporating a band switching VCO having a low KVCO tuning factor enabling operation with low supply voltage and low susceptibility to noise and frequency pulling. The VCO has a low tuning factor that covers only a small portion of the operating frequency range, depending on the number of bands into which the frequency range is divided. The normal phase locked loop operation of the synthesizer is preceded by an open loop band selection procedure which results in faster lock time and a lower required tuning voltage range for the VCO. The frequency band selection is made using frequency measurements. Alternatively, a band select LUT and channel LUT are generated a priori during a calibration stage in order to speed frequency acquisition and band selection.

Abstract: A suspended printed inductor (SPI) connected in parallel to a suspended interdigital capacitor (SIC) so as to form a parallel resonant circuit that is nearly independent of variations in PCB etching tolerances. This combination of SPI and SIC functions to resonate at a center frequency and with similar parallel resonant circuits can be used to form RF filters having any desired order. Using the parallel resonant combination of SPI and SIC, a RF filter can be constructed whose electrical properties are nearly insensitive to variations in PCB parameters and etch processing. The sensitivity of the spiral suspended printed inductor in combination with the suspended printed interdigital capacitor to PCB parameters such as dielectric constant and PCB height is greatly reduced. Further, the parallel combination of suspended printed spiral inductor and suspended interdigital capacitor is nearly insensitive to PCB etching tolerances. SPIs and SICs are characterized by the absence of a ground plane.

Abstract: A novel inductor termed a suspended printed inductor (SPI) and an LC-type printed filter constructed using the suspended printed inductor is disclosed. The LC-type suspended printed filter is formed over any suitable substrate material, such as a dielectric substrate, with greatly reduced effects on filter performance due to the characteristics of the material. SPIs are characterized by the absence of a ground plane. A ground plane may physically still exist but it is located at a sufficient distance form the printed circuit board such that the distance can be considered virtual infinity from an RF circuit perspective. A number of different types of inductors can be fashioned as a suspended printed type inductor, including serpentine line inductors or transmission line inductors. The suspended printed inductor can be utilized to construct numerous types of filters such as low pass, high pass, band pass, band stop or any combination thereof.