Abstract: An apparatus includes a Doherty PA having an input, an output manifold, and peaking and main amplifier paths. The peaking amplifier path includes peaking amplifier(s) configured to amplify signals over multiple frequency bands. A main amplifier path is separate from the peaking amplifier path until the main amplifier path terminates in the output manifold. The main amplifier path includes main amplifier(s), configured to amplify signals over the multiple frequency bands, and a multiple-band matching network coupled to the output of the main amplifier(s) and terminating in the output manifold. The multiple-band matching network includes multiple signal paths, one for each of the multiple frequency bands. Each signal path includes circuitry configured to pass signals to the output manifold from only a unique one of the multiple frequency bands and to reject signals from others of the multiple frequency bands. The circuitry for each signal path includes a resonant tank.

Abstract: An apparatus includes a Doherty PA having an input, an output manifold, and peaking and main amplifier paths. The peaking amplifier path includes peaking amplifier(s) configured to amplify signals over multiple frequency bands. A main amplifier path is separate from the peaking amplifier path until the main amplifier path terminates in the output manifold. The main amplifier path includes main amplifier(s), configured to amplify signals over the multiple frequency bands, and a multiple-band matching network coupled to the output of the main amplifier(s) and terminating in the output manifold. The multiple-band matching network includes multiple signal paths, one for each of the multiple frequency bands. Each signal path includes circuitry configured to pass signals to the output manifold from only a unique one of the multiple frequency bands and to reject signals from others of the multiple frequency bands. The circuitry for each signal path includes a resonant tank.

Abstract: A method for correcting high order IM products is described. The method includes creating a modified input signal by increasing one or more portions of an input signal (such as the whole time domain signal for example). The input signal consists of a desired signal and other non-linear products. Each of the one or more portions includes high order IM products. A pre-distorted signal is created by pre-distorting the modified input signal in accordance with a finite signal plan. An output signal is generated by amplifying the pre-distorted signal. Apparatus and computer-readable media are also described.

Abstract: A Power Amplifier (PA) exhibits non-linear characteristics as a result of Amplitude Modulation-Phase Modulation (AM-PM) conversions resulting in intermodulation. Inter-modulation affects the RF signal spectrum at the output of the PA. The invention presents a method and apparatus for reducing intermodulation generated at the output of a PA as a result of AM-PM conversion. Presented is a RF power detector utilized in feedback control circuitry where the induction of odd-order harmonics into the feedback path acts to reduce AM-PM intermodulation at the output of the PA. The RF power detector comprises an detector input for receiving RF power and a detector output containing a pre-corrected detected voltage. The RF power detector comprises a pre-correcting circuit for generating odd-order harmonics at a specific power level. The pre-correcting circuit induces odd-order harmonics into the detected portion of output power allowing feedback control circuit to compensate for AM conversions.

Abstract: A method and apparatus for improving loop stability and speed of a power control loop. Adjacent channel interference in the ramp-up and ramp-down (transient) of a TDMA burst is reduced. The present invention is used in a burst when the transient response and loop speed are important in the design of the control loop. The loop bandwidth variation resulting from linear conversion power detector and PIN diode RF attenuators in the loop is reduced by reducing the upper end of the loop bandwidth and increasing the lower end of the loop bandwidth. The upper limit of the loop bandwidth determines the loop stability and the lower limit of the loop bandwidth determines the minimum speed of the loop. A reference signal is sampled and processed to set a gain of a feedback loop in the power control loop.

Abstract: A compensated RF power detector utilized in power control circuits for preventing power amplifier saturation. A power amplifier uses a power control circuit to maintain the power amplifier as efficiently and linearly as possible without distortion. The operating point of the power amplifier is defined as close to the 1 dB gain compression point as possible for maximum efficiency and linearity with minimum distortion. However, extreme temperature conditions affect the 1 dB gain compression point causing the power amplifier to operate too close to saturation resulting in distortion or spectral growth. In an embodiment, the compensated RF power detector comprises a RF power detector and a variable RC circuit. The RF power detector has a RF input for receiving RF power, a detector output for supplying a compensated detected voltage and, a detecting diode for generating a detected voltage in response to the received RF power.

Abstract: A temperature compensated variable attenuator comprising a variable attenuator having at least one diode with temperature variations across the at least one diode producing a temperature offset signal. A bias source coupled to the variable attenuator supplies a biasing signal to the at least one diode through a temperature compensation source. The temperature compensation source is coupled between the bias source and the variable attenuator with the temperature compensation source comprising at least one diode capable of producing a temperature offset signal approximately equivalent to the temperature offset signal produced by the first at least one diode. The approximate temperature offset signal subtracted from the biasing signal produces a temperature compensated bias signal that is supplied to the variable attenuator.

Abstract: A precision-controlled logarithmic amplifier having reduced interference parameters. In an embodiment, the invention comprises a logarithmic amplifier having an output signal providing a logarithmic representation of an input signal. A precision-control circuit is coupled to the logarithmic amplifier. The precision-control circuit produces a bias and a saturation current that act to reduce the effects of bias and saturation currents that are produced in the logarithmic amplifier and affect the output signal of the logarithmic amplifier.

Abstract: A controlled detector circuit for generating a detector current to the input of a selected circuit. An unwanted operational voltage is generated on the input of the selected circuit affecting the precision of the detector circuit. The controlled detector circuit comprises a detector circuit having an RF input for detecting a RF signal and a detector output for providing the detector current. Operation of the detector circuit generates a voltage drop affecting the precision of the detector current. A control circuit having a control output connected to the detector output generates a control voltage for reducing the unwanted parameters affecting the precision of the detector current.

Abstract: A TM mode dielectric resonator and a filter comprising such a resonator. The resonator includes metallic walls defining a cavity. A dielectric resonator body is accommodated within the cavity. An end surface of the dielectric resonator body is located in the vicinity of one cavity wall, so as to provide a spacing between said end surface and said cavity wall, at least in a region corresponding to a portion of said end surface. The spacing can be obtained by washers, arranged between the dielectric resonator body and said cavity wall. It can also be obtained by means of a recess in said cavity wall, one or more protrusions on said cavity wall, or a metallic or dielectric ring arranged between the dielectric resonator body and said cavity wall.

Abstract: A dual-band filter providing a bandpass characteristic over a first predetermined range of frequencies, and a notch, or band-reject characteristic over a second predetermined range of frequencies. In one embodiment, the notch characteristic occurs within the bandpass characteristic, yielding a filter frequency response with two asymmetric passbands separated by a reject band. This is particularly suited to cellular Band A receive filter applications, but the design is easily adapted to other uses. Appropriate tuning can restore symmetry to the passbands.

Abstract: A multichannel combiner includes a plurality of input ports for connection to associated transmitters, narrow bandpass filters associated with each port, and an output port for connection to an antenna system. The output impedance of the filters is selected to be substantially lower than that used in conventional combiners, such that undesired reactance produced in the combiner over its operating range is much reduced. The combiner further includes an impedance transformer to match the low output impedance of the filters to the design impedance of the antenna system.

Abstract: An RF filter having a housing defining a cavity with plural elongated resonators and plural resonator decouplers adjacent each of plural pairs of the resonators in the housing. The decouplers are grounded adjacent each of their ends only to the housing to provide an enhanced resonator decoupling effect. The filter may instead comprise a dielectric block with resonator holes and resonator decoupler holes each appropriately metalized with the decoupler holes being grounded at each end at external metalized block surfaces.