Abstract: A circuit includes a passive low gain low noise amplifier (LNA) configured to receive a communication signal, an active low gain LNA configured to receive the communication signal, a shared coupling circuit, outputs of the passive low gain LNA and the active low gain LNA coupled to the shared coupling circuit, an output circuit, an output of the shared coupling circuit coupled to the output circuit, and a high gain LNA configured to receive the communication signal, the high gain LNA coupled to the output circuit along a path that bypasses the shared coupling circuit.

Abstract: Antenna structures and methods of operating the same of an electronic device are described. One wearable electronic device includes a housing of conductive material and an antenna structure disposed on or within a band that is used to affix to a user. The antenna structure includes a first connector, a second connector, and a first antenna element. The first and second connectors extend out from sides of the band and electrically couple to a RF feed and a ground point when the first and second connectors are physically coupled to the housing. The RF circuitry is operable to cause a first current flow on at least the first antenna element via the first connector to radiate electromagnetic energy in a first frequency range.

Abstract: Database access is described, for example, where data in a database is accessed by an inference engine. In various examples, the inference engine executes inference algorithms to access data from the database and carry out inference using the data. In examples the inference algorithms are compiled from a schema of the database which is annotated with expressions of probability distributions over data in the database. In various examples the schema of the database is modified by adding one or more latent columns or latent tables to the schema for storing data to be inferred by the inference engine. In examples the expressions are compositional so, for example, an expression annotating a column of a database table may be used as part of an expression annotating another column of the database.

Abstract: A receiver for nano communication includes a power source including a cathode and an anode; a cathode unit connected to the cathode of the power source, the cathode unit including a nano device configured to receive a wireless signal modulated according to a predetermined modulation scheme, have at least two different resonant frequencies, and resonate based on a frequency of the wireless signal and the at least two different resonant frequencies; and an anode unit connected to the anode of the power source, the anode unit being configured to detect electrons emitted from the nano device, and demodulate a the wireless signal based on a pattern of the detected electrons.

Abstract: Passive RF devices are disclosed that communicate using a wireless network protocol. The device includes an antenna operable to receive a radio frequency (RF) signal from a RF source that transmits the RF signal based on a wireless network protocol. The device further includes circuitry operable to derive power from the RF signal. With the power derived from the RF signal, the circuitry is further operable to read data from a memory, to encode the data based on the wireless network protocol, and to modulate the RF signal to include the encoded data. The antenna is further operable to transmit the modulated RF signal based on the wireless network protocol for reception by the RF source or another passive RF device.

Abstract: Systems and methods for providing single-ended to differential signal conversion are described. A single-ended voltage signal may be received from an input of a low noise amplifier. The single-ended voltage signal may be coupled to a first input stage to match a source impedance of the single-ended voltage signal to a predetermined output impedance. The single-ended voltage signal with the predetermined output impedance may be output as a first voltage signal to a first converting stage. An input bias voltage may be provided to the first converting stage to bias the first voltage signal. The biased first voltage signal may be output as a first differential-ended current signal to an output of the low noise amplifier.

Abstract: An antenna assembly for receiving the GPS signals in a global positioning system (GPS) receiver module automatically orients the antenna to better receive the GPS signals. The antenna is oriented by a positioner (e.g., a counterweight) that automatically rotates a frame on which the antenna is mounted. The GPS receiver module may also include multiple antennas oriented in different directions to maintain good reception of the GPS signals in any position. The multiple antennas are oriented in a manner so that the poor reception range an antenna is covered by other antennas. Signals from multiple antennas may be combined or chosen for processing by a GPS processor. Also, multiple GPS receiver modules may be deployed in close proximity so that wireless communication between the GPS receiver modules may be established.

Abstract: An antenna with a built-in filter for use in an electronic device includes: an antenna element; and a circuit board unit connected to the antenna element, wherein the circuit board unit includes: a filter circuit that filters input and output signals of the antenna element; and a matching circuit that performs impedance matching of the antenna element.

Abstract: A high-frequency amplifier includes: an amplification section having a function to convert an input signal from a voltage signal into a current signal and output the current signal; output terminals; and a load circuit which is connected to the output node of the amplification section and outputs the current signal output by the amplification section to the output terminals as a voltage signal.

Abstract: Apparatus and methods of manufacture for a wideband RF mixer are provided. The RF mixer includes an input, an LO input, and an output. A variable impedance tuner is disposed in an input signal path between the input port and the RF mixer, and a variable impedance tuner is disposed in an output signal path between the output and the RF mixer. The impedances of the variable impedance tuners are controllable for a particular frequency of operation with one or more digital or analog control signals.

Abstract: A method for tuning a filter is provided. The amplitude of a first signal (I1) is compared with the amplitude of a comparison signal. The first signal is generated with a first filter, which receives a first input signal, and there is a phase difference between the first signal (I1) and the comparison signal. A tuning signal is then generated based on differences between the amplitudes of the first signal (I1) and the comparison signal. The tuning signal compensates for any phase and/or amplitude offset in the first signal (I1).

Abstract: A mobile wireless device enables effective use of space in a case while reducing degradation of antenna gain and maintaining communication quality even if a plurality of antennas having different frequency bands are arranged close to one another. A magnetic antenna has a first switch unit, a second switch unit, and a concentrated constant circuit which are added to a wiring pattern at the side near to a main antenna, so that a first path and a second path can be selected. Under a predetermined condition, a CPU controls the first switch and the second switch to electrically connect terminal (A1) to terminal (B1) and electrically connect terminal (A2) to terminal (B2), thereby forming the first path; and electrically connect terminal (A1) to terminal (C1) and electrically connect terminal (A2) to terminal (C2), thereby forming the second path connected via the concentrated constant circuit.

Abstract: In accordance with some embodiments of the present disclosure an attenuating circuit comprises a balun configured to receive a radio frequency (RF) signal at first and second input ports and configured to output the RF signal. The circuit further comprises an attenuator coupled in parallel with the first and second input ports. A power level of the RF signal output by the balun is based at least partially on an impedance of the attenuator. The attenuator comprises a resistor ladder configured to receive at least a portion of the RF signal and a plurality of switches coupled to the resistor ladder. The plurality of switches are configured to open and close such that the impedance of the attenuator is a function of which switches are open and closed. Therefore, the power of the RF signal is controlled based at least on the opening and closing of the switches.

Abstract: In one embodiment, the present invention includes an amplifier having a transistor stage coupled between a supply voltage and a bias current. The transistor stage has an input to receive a radio frequency (RF) input signal obtained from an antenna. The amplifier has an input impedance that is unmatched to a source impedance of the antenna. In some embodiments, this unmatched input impedance may be substantially greater than the source impedance, and may further be controlled based on a strength of the RF input signal.

Abstract: One embodiment relates to a circuit for efficient wireless communication. The circuit includes a communication port adapted to be coupled to an antenna feed. Multiple communication paths stem from the communication port, where different communication paths are associated with different frequency bands. Multiple phase shift selection circuits are respectively associated with the multiple communication paths. The phase shift selection circuits have different respective impedances relative to the communication port and the respective impedances vary for the different frequency bands. Other methods and systems are also disclosed.

Abstract: A tunable bandpass filter (10) is provided. An RF signal is provided at an input of the tunable bandpass filter, and a level shifted control signal (V1, V2) inputted to the tunable bandpass filter (10) switches a first arrangement and a second arrangement of one or more tuning portions (15, 17-1, 17-2, 17-3) in or out of the tunable bandpass filter using a GaAs FET switch. The first arrangement is coupled to the second arrangement using an inductor (13). An RF signal having a desired predetermined frequency at an output of the tunable bandpass filter (10) is produced by the switching. The tuning portions include the GaAs FET switch (15), a first capacitor (17-1) connected at a first signal terminal of the GaAs FET switch and a second capacitor (17-2) connected between a second signal terminal of the GaAs FET switch and ground. Each of the tuning portions can be arranged in parallel with one another.

Abstract: A tunable bandpass filter (10) is provided. An RF signal is provided at an input of the tunable bandpass filter, and a level shifted control signal (V1, V2) inputted to the tunable bandpass filter (10) switches a first arrangement and a second arrangement of one or more tuning portions (15, 17-1, 17-2, 17-3) in or out of the tunable bandpass filter using a GaAs FET switch. The first arrangement is coupled to the second arrangement using an inductor (13). An RF signal having a desired predetermined frequency at an output of the tunable bandpass filter (10) is produced by the switching. The tuning portions include the GaAs FET switch (15), a first capacitor (17-1) connected at a first signal terminal of the GaAs FET switch and a second capacitor (17-2) connected between a second signal terminal of the GaAs FET switch and ground. Each of the tuning portions can be arranged in parallel with one another.

Abstract: A broadcast receiver for use in a mobile communication terminal includes a receiving antenna and an antenna tuning circuit connected to the receiving antenna. The receiving antenna receives broadcast signals tuned to the resonant frequency of the antenna tuning circuit by changing the resonant frequency. The antenna tuning circuit includes an unwanted voltage suppression circuit that suppresses an unwanted voltage generated due to the rectification effect of a varactor when the receiving antenna receives transmission signals output from the transmission antenna of the mobile communication terminal.

Abstract: A variable capacitance device has a piezoelectric driving part, a movable electrode, a fixed electrode, a dielectric film and a driving control unit. The piezoelectric driving part has a piezoelectric film, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on an undersurface of the piezoelectric film and electrode slits which separate the upper electrode and the lower electrode into two, respectively. The movable electrode is provided via the electrode slits at one end of the piezoelectric driving part. The fixed electrode is disposed opposite to the movable electrode via a gap. The dielectric film is disposed opposite to the movable electrode via the gap and provided on the fixed electrode. The driving control unit adjusts a distance between the movable electrode and the fixed electrode to reduce a fluctuation of a predetermined capacitance of a variable capacitor formed between the variable electrode and the fixed electrode.

Abstract: This document discloses, among other things, a front end circuit having a selectable center frequency. The center frequency is selected based on a control signal proportional to a phase difference between a reference frequency and an amplifier output. A resonant frequency of a tank circuit coupled to the amplifier is tuned using the control signal.

Abstract: The present invention relates to a hybrid balun apparatus and a receiver thereof. The hybrid balun apparatus comprises a passive unit, a first active unit, and a second active unit. The passive unit receives an input signal, and outputs an in-phase signal having an identical phase compared to the input signal and an inverse-phase signal having an inverse phase compared to the input signal. The first active unit compensates the in-phase signal of the passive unit corresponding to the input signal. The second active unit compensates the in-phase signal of the passive unit in response to the input signal.

Abstract: A tunable bandpass filter (10) is provided. An RF signal is provided at an input of the tunable bandpass filter, and a level shifted control signal (V1, V2) inputted to the tunable bandpass filter (10) switches a first arrangement and a second arrangement of one or more tuning portions (15, 17-1, 17-2, 17-3) in or out of the tunable bandpass filter using a GaAs FET switch. The first arrangement is coupled to the second arrangement using an inductor (13). An RF signal having a desired predetermined frequency at an output of the tunable bandpass filter (10) is produced by the switching. The tuning portions include the GaAs FET switch (15), a first capacitor (17-1) connected at a first signal terminal of the GaAs FET switch and a second capacitor (17-2) connected between a second signal terminal of the GaAs FET switch and ground. Each of the tuning portions can be arranged in parallel with one another.

Abstract: A distributor arranged between a tuner module and an antenna, the tuner module including a first input portion and a second input portion for inputting a satellite broadcast signal transmitted from an artificial satellite and a ground broadcast signal transmitted from a ground base station respectively, and the antenna receiving either one of the broadcast signals. The distributor includes a first connector portion connected to the antenna; a second connector portion connected to the first input portion; a third connector portion connected to the second input portion; and a junction connecting portion distributing the signal inputted to the first connector portion to the second and the third connector portions. A drive voltage of the antenna inputted from the first input portion is outputted to the antenna. The voltage outputted to the antenna is fed back to the second input portion through the junction connecting portion and the third connector portion.

Abstract: Aspects of a method and system for utilizing a frequency modulation (FM) antenna for near field communication (NFC) and radio frequency identification (RFID) are presented. Aspects of a system for utilizing an FM antenna for NFC and RFID may include a tuning control block that enables configuration of at least one capacitor array to control a frequency for reception of signals. A processor may enable configuration of an antenna for the reception of signals wherein the frequency for the received signals is utilized for FM signal reception, and at least one of: NFC signal reception, and RFID signal reception.

Abstract: A tunable bandpass filter (10) is provided. An RF signal is provided at an input of the tunable bandpass filter, and a level shifted control signal (V1, V2) inputted to the tunable bandpass filter (10) switches a first arrangement and a second arrangement of one or more tuning portions (15, 17-1, 17-2, 17-3) in or out of the tunable bandpass filter using a GaAs FET switch. The first arrangement is coupled to the second arrangement using an inductor (13). An RF signal having a desired predetermined frequency at an output of the tunable bandpass filter (10) is produced by the switching. The tuning portions include the GaAs FET switch (15), a first capacitor (17-1) connected at a first signal terminal of the GaAs FET switch and a second capacitor (17-2) connected between a second signal terminal of the GaAs FET switch and ground. Each of the tuning portions can be arranged in parallel with one another.

Abstract: A communications device including communications circuitry, tunable filter circuitry including a node configured to pass a signal between an antenna and the communication circuitry, and control circuitry configured to cause energy in the tunable filter circuitry to be adjusted for a time period and configured to determine a resonant frequency of the tunable filter circuitry from oscillations on the node caused by the energy subsequent to the time period is provided.

Abstract: Disclosed are systems and methods which utilize an image reject mixer in an out-of-band mixer application such as in a forward data channel frequency converter. For example, according to a preferred embodiment, an image reject mixer is utilized to provide a relatively high degree of image rejection with respect to an out-of-band signal, thereby relaxing the requirement for filtering in the signal path leading to the mixer circuitry. Preferred embodiments of the invention are substantially or fully implemented utilizing integrated circuit technology.

Abstract: A system for wireless communications is provided. The system includes a hand-held wireless communications device, such as a cell phone. An antenna is connected to the cell phone. The antenna radiates radio waves over an area of less than 360 degrees of arc, such as in a cardioid or hemisphere. The antenna is oriented such that hemisphere is in the direction away from a head of a user of the cell phone.

Abstract: A frequency agile sequential amplifier circuit that includes first and second RF amplifiers coupled by a SAW delay line, a double balanced mixer coupling the first RF amplifier to the SAW delay line, the output of the first RF amplifier providing a signal as a first input to the double balanced mixer and a variable pulse generator coupled to both said first and second RF amplifiers to cause them to sequentially and alternately conduct, and a divide/2 circuit coupling said variable pulse generator to said double balanced mixer as a second input at ½ the rate of said RF amplifiers to cause the sequential amplifier circuit to achieve frequency agility and to substantially maintain its sensitivity.

Abstract: Integrated RF components in the radio frequency (RF) front end of a communication device. The RF front end includes an antenna function for converting between radiated and electronic signals, includes a filter function for limiting signals within operating frequency bands, an amplifier function for boosting signal power and a mixer function for shifting frequencies between RF and lower frequencies. The receive antenna function is separate from the transmit antenna function where a common integrated filter/antenna (filtenna) is employed for both the receive path and the transmit path.

Abstract: With the rising popularity in wireless personal communication systems (PCS), there is a need for low-power, low-cost radio receivers. Low cost can be achieved by integrating the required functions as much as possible, thus minimizing the number of off-chip components. The present invention discloses a novel topology for integrating an image reject filter with a traditional low-noise amplifier (LNA) for use in the front-end of a superheterodyne receiver. Previous topologies employing additional filter stages after the LNA have suffered from poor performance and excessive current consumption. Advantageously, the topology of the present invention requires minimal additional circuitry to perform the filtering function, uses only minimal additional current and does not suffer from the same performance limitations as previous topologies.

Abstract: A tuner includes a tunable filter for selecting a desired RF signal in response to a tuning control signal and a tunable image trap for rejecting the undesired image signal corresponding to the desired RF signal responsive to the tuning control signal coupled in cascade between an RF amplifier and a mixer. The tunable trap also serves as an impedance transformation element between the tunable filter and said mixer. The arrangement is particularly useful in a tuner in which the frequency range of the local oscillator signal is below the frequency range of the received RF signals.

Abstract: In order to select one or more microwave signals from among the signals which it receives, the reception device comprises switching circuits. The switching circuits are commanded by command signals. According to the invention, a switching circuit command signal consists of at least two sinusoidal signals generated according to the principle of voice-frequency dialling. The invention applies more particularly to the reception of signals from telecommunication and/or telebroadcast satellites.

Abstract: This invention provides terpenoid lactone compounds, and processes for producing the terpenoid lactone compounds, which comprise cultivating Oidiodedron griseum FERM BP-5778 and then isolating the terpenoid lactone compounds from the fermentation broth. The present invention also provides a pharmaceutical composition comprising the teipenoid lactone compound, which is useful in the treatment of IL-1 and TNF mediated diseases or the like.

Abstract: A tunable antenna system for operation over a predetermined frequency range includes a high Q antenna having a length and width each significantly less than a quarter wavelength within the predetermined frequency range. A controllable reactive element is coupled to the antenna and has a variable reactance for tuning the antenna in a high Q resonant circuit to the frequency of a desired signal in the frequency range coupled to the antenna. An antenna tuning circuit responsive to the frequency to which the antenna is tuned provides an antenna tuning signal to the controllable reactive element so that the antenna remains tuned to the frequency of the desired signal.

Abstract: A selective RF circuit for a double conversion tuner includes three double tuned bandpass circuits, each of which is tunable over approximately one-third of the tuning range. Switching diodes are used at the input and the output of each of the bandpass sections for selectively activating one of the bandpass sections and deactivating the remaining ones in response to a bandswitching signal. Operational amplifiers or other devices supply the input and output switching diodes by providing a current sink for the active bandpass and current sources for the inactive bandpasses.

Abstract: In a receiver, a tunable parallel resonant circuit (PRC2) is coupled to an input (IN) of a transistor circuit (MOIC) via a coupling network (CNW). The coupling network (CNW) lacks a varicap diode but includes a coupling resistor (Rc) in series with a coupling capacitor (Cc).

Abstract: In a system for contactless power and data transmission, a transmitting or receiving station has at least one transmitting or receiving resonant circuit which is driven by an integrable control circuit. The integrated control circuit has a multiplicity of capacitors which can be switched in, in parallel with the resonant circuit. A device is provided for driving the switching device.

Abstract: In a portable radio communication apparatus, a matching circuit is electrically connected to an antenna when the antenna is retracted into a casing. In this condition, the antenna and a feed circuit are matched as desirably as when the antenna is extended from the casing.

Abstract: A balanced bandpass preamplifier assembly (23) is disclosed for use in a locator (10) for locating a beacon transmitter (18) housed within an underground boring device (12). The bandpass preamplifier assembly (23) includes a balanced bandpass filter (28) of the Butterworth type with second order filter characteristics. The preamplifier assembly (23) provides reception of beacon frequencies at two distinct frequencies, preferably 29.430 KHz and 32.768 KHz. The antenna (14) of the . locator (10) forms the series inductance in the bandpass filter (28).

Abstract: A non-contact IC card capable of communicating with external equipment at various communication frequencies. An antenna circuit of variable frequency and a frequency switching circuit for supplying communication clock signals of variable frequency to a modulator-demodulator circuit are provided so that communication is performed by switching a constant of the antenna circuit and the frequency of the communication clock signal generated from the frequency switching circuit in accordance with the frequency of external equipment with which communication is effected.

Abstract: A phase comparator (91) makes a phase comparison between a frequency-divided signal from a frequency divider (98) and a reference oscillation signal from a reference signal oscillator (90). The phase error signal obtained from the comparison is passed through an LPF (92) to yield a frequency control signal, which is applied to a VCO (94). An oscillated signal from is frequency-multiplied by a frequency multiplier (96). The multiplied output oscillation signal SO is frequency-divided by the frequency divider (98) and output to the phase comparator (91). The multiplied output oscillation signal SO is sent out to a receiver circuit (43) and a transmitter circuit (45).

Abstract: A remote, unpowered passive transmitter has a tank circuit, a coil and capacitor. The capacitor is variable to vary the frequency of the tank. This is coupled to a receiver having a hybrid splitter. With four ports, two balanced, opposing ports connect to two lines terminating in line impedance. The tank couples into one of the two line so that a difference signal is formed and output. Line loading forms a signal indicating tank frequency.

Abstract: A selective calling receiver comprises two separate bands having an antenna circuit for tuning incorporated therein. The first band has a first antenna and tuning capacitors incorporated therein and stoppers formed and arrayed on the outer surface thereof. Predetermined points are provided to the first antenna, providing different effective antenna lengths, respectively. The respective stoppers are provided with electrodes which are connected to the predetermined points of the first antenna through the tuning capacitors, respectively. The second band has a second antenna and a hook. The hook can be engaged with a selected one of the stoppers of the first band depending on the user's wrist thickness. The hook comprises a conductor electrically connected to the second antenna. When engaged with a selected one of the stoppers, the hook brings into electrical contact with the corresponding electrode to form the antenna circuit.

Abstract: A wristwatch paging receiver is provided with an antenna matching network that automatically retunes the network at the beginning of a listening interval. During the retuning operation, a control signal is applied to a variable tuning element in the matching network, such as a varactor diode, and is swept from a minimum value to a maximum value. This sweeping is desirably performed in discrete voltage steps that correspond to unit increments of varactor capacitance. A feedback signal from the receiver, such as an AGC signal, is monitored during this operation to note which varactor bias signal yields the maximum AGC signal. After the sweep is concluded, the apparatus applies to the varactor the bias voltage that yielded the maximum AGC signal during the sweeping operation. This bias voltage is maintained through the end of the listening interval. At the beginning of the next listening interval, the process may be repeated.

Abstract: An inductance element is arranged to parallel resonate with a ground stray capacitance component of an antenna element on a motor vehicle and a feeder cable to a receiver. Matching means is provided to compensate for a Q-factor of the parallel resonance for improving a reception gain over a wide range in a reception band.

Abstract: The present invention is for a highpass input circuit for a television receiver having an additional trap at a predetermined frequency, e.g. CB frequencies. A M derived constant K high pass filter having an intermediate pi configured filter section is provided with an additional inductor in the shunt leg of the pi section for resonating with the bridge capacitance of the pi section and forming an additional trap at the predetermined frequency. The additional inductor is physically formed by an electrically conductive path etched on a printed circuit board.

Abstract: RF-input stage for TV receivers comprising a field effect transistor in grounded source circuit configuration and a frequency-dependent coupling network arranged between the gate electrode of the field effect transistor and an aerial input for selecting TV signals and transforming the signal impedance. The frequency-dependent coupling network is terminated with a resistor which is arranged between the gate electrode of the field effect transistor and ground and whose value has been chosen so that on the one hand this resistor terminates in conjunction with the input impedance of the field effect transistor the frequency-dependent coupling network with an acceptable reflection factor and on the other hand forms in conjunction with the output impedance of the frequency-dependent coupling network an impedance at which the noise contribution of the field effect transistor is at least substantially at its lowest.

Abstract: A noise-suppressing circuit suitable for insertion between a receiving antenna and an RF receiver to suppress noise in the RF signal received by the receiving antenna includes a bandpass filter circuit connected to receive as an input the RF signal received by the antenna, and connected in series to a blanking circuit which employs a JFET to remove from the filtered RF signal the unwanted noise spikes. The bandpass filter attenuates the components of the RF signal that have frequencies outside of the passband, and after the blanking circuit has removed the noise spikes, it passes the remainder of the filtered RF signal to the RF receiver. In a preferred embodiment, the bandpass filter circuit includes a parallel resonant circuit, and the blanking circuit includes a series resonant circuit connected between the drain and the gate of JFET of the blanking circuit.

Abstract: Serially connected UHF and VHF tuners and control of the lead lengths of the conductors to the tuners from the antenna permit utilization of a single antenna for both the UHF and VHF tuners without need for a crossover network. If the lead lengths are selected to present minimal impedance at the highest UHF frequencies to be received, the intrinsic input impedance for each tuner can be utilized as the crossover network, allowing UHF signals to be applied to the UHF tuner and VHF signals to be applied to the VHF tuner. By use of both external and internal leads in conjunction with a terminal block, each of the tuners is made available for dual antenna operation.