Abstract: An EOS/ESD protection apparatus includes a voltage detection circuit, a controlling circuit having a switch unit, an inverter circuit, and a clamp transistor. The voltage detection circuit is configured to detect whether an over voltage event occurs in a power supply line to generate a switch control signal. The switch unit is turned on/off to generate a voltage control signal according to the switch control signal. The inverter circuit has an output and an input coupled to the voltage control signal transmitted from the controlling circuit. The clamp transistor has a control terminal coupled to the output of the inverter and is configured to be turned on when the over voltage event occurs in the power supply line.

Abstract: An overvoltage detector for an RF switch is disclosed. The overvoltage detector is made up of circuitry having a detector output that couples to a controller, a body voltage input that couples to a charge pump, and a body voltage output that couples to a body terminal of the RF switch. The overvoltage detector is configured to detect an overvoltage across the RF switch by monitoring body leakage current flowing between the body voltage input and the body voltage output. Upon detecting body leakage current over a predetermined level, the overvoltage detector generates an overvoltage signal at the detector output to indicate an overvoltage across the RF switch.

Abstract: A power theft inspection apparatus is provided with: a controlling device configured to open a third switch unit between a power reception unit and a power reception control circuit of a power receiving apparatus at the start of a power theft inspection, then open a first switch unit between a power transmission unit and a power supply unit of a power transmitting apparatus after the opening of the third switch unit, and then close a second switch unit configured to short-circuit the power transmission unit of the power transmitting apparatus after the opening of the first switch unit; and a determining device configured to determine whether or not there is power theft according to a current detected by a first current detecting device configured to detect a current in the power transmission unit of the power transmitting apparatus upon the power theft inspection.

Abstract: The present disclosure relates to antenna swapping for a wireless, e.g., cellular, radio system. In particular, embodiments of a single-die antenna swapping switching circuit are disclosed. In some embodiments, the single-die antenna swapping switching circuit enables antenna swapping in a wireless device using only two coaxial cables or transmission line connections regardless of an order of an antenna multiplexer of the wireless device. This results in significant space savings, particularly as the order of the antenna multiplexer increases, compared to antenna swapping techniques that require a pair of coaxial cables or transmission lines for each order of the antenna multiplexer. In addition, the single-die antenna swapping switching circuit is designed to be located between a radio front-end system and the antenna multiplexer such that intermodulation distortion and harmonics resulting from the switches comprised in the single-die antenna swapping switching circuit are mitigated.

Abstract: Provided are superconducting circuits, methods of operating these superconducting circuits, and methods of determining processing conditions for operating these superconducting circuits. A superconducting circuit includes a superconducting element, a conducting element, and a dielectric element disposed between the superconducting element and the conducting element. The conducting element may be another superconducting element, a resonating element, or a conducting casing. During operation of the superconducting element a direct current (DC) voltage is applied between the superconducting element and the conducting element. This application of the DC voltage reduces average microwave absorption of the dielectric element. In some embodiments, when the DC voltage is first applied, the microwave absorption may initially rise and then fall below the no-voltage absorption level.

Abstract: A mobile device includes an antenna, an ESD (Electrostatic Discharge) protection component, a plurality of branches, and a switch. The antenna is configured to transmit and receive an RF (Radio Frequency) signal. The branches provide different inductances or different capacitances, and are respectively coupled to a ground voltage terminal. The switch is coupled through the ESD protection component to the antenna, and switches between the branches according to a control signal such that the antenna is capable of operating in a plurality of frequency intervals. The ESD protection component is configured to protect the switch from being damaged.

Abstract: An intrinsic safety approach is provided for a battery powered communication device. Sparking is prevented at radio contacts during attachment and removal of a battery (104, 204, 304, 404) from a radio (102, 202, 302, 402) through the use of switches (112, 212, 312, 412/424) to isolate the radio capacitors from the radio contacts and/or dissipate energy from the radio capacitor through a discharge resistor (214, 314, 414).

Abstract: An apparatus is provided that includes a plurality of portable wireless transmitter units, a plurality of digital receiver modules that alternate transmitting wireless synchronization pulses and that receive information from the plurality of transmitter units synchronized to the synchronization pulses, a receiver control unit in communication with each of the receiver modules that coordinates transmission of synchronization pulses among the plurality of digital receiver modules in accordance with a predetermined transmission sequence and a system that receives the information from at least some of the microphone transmitter units through the receiver modules and delivers the information exclusively to a geographic area proximate a source of the audio information.

Abstract: A data module operable in a wireless communication system is provided. The data module comprises a plurality of circuit components, one or more temperature sensors, and a thermal management unit. The temperature sensors are configured to determine the temperature of a corresponding circuit component. The thermal management unit is configured to determine one or more thermal characteristics of the data module based on the temperature determinations, and to generate one or more power control point signals indicating whether to adjust corresponding operating characteristics of a target component based on the determined thermal characteristics.

Abstract: A high-frequency device includes a wireless IC chip and a board which is coupled to the wireless IC chip and electrically connected to radiator plates, and an inductor and/or a capacitance are provided as a static electricity countermeasure element in the board. The inductor is connected in parallel between the wireless IC chip and the radiator plates, and its impedance at the frequency of static electricity is less than an impedance of the wireless IC chip.

Abstract: An automatic fuse architecture is described. An incoming signal is received and detected to determine whether the signal exceeds a threshold value.

Abstract: A FM receiver comprises an IF filter, a demodulator and a decoder. The IF filter generates an RSSI and a FM modulated signal in response to a FM signal. The demodulator comprises a duty-to-voltage amplifier for amplifying a peak of a MPX signal. The duty-to-voltage amplifier comprises a current source, a switch and a current splitter. The current source generates a current. The switch controls a flow of the first current in response to a PWM signal. The current splitter splits the flow of the current into a sub-flow in response to the RSSI. The peak of the MPX signal is proportional to the sub-flow. The decoder receives the MPX signal to generate an audio signal to play sound.

Abstract: Disclosed herein is a terrestrial broadcasting receiving module including: an antenna receiving a wireless signal; a distributing unit distributing and outputting the wireless signal into a wireless signal including a VHF band signal and a wireless signal including a UHF band signal; a VHF processing unit generating and outputting a VHF intermediate frequency signal from the wireless signal including the VHF band signal; a UHF processing unit generating and outputting a UHF intermediate frequency signal from the wireless signal including the UHF band signal; and a demodulating unit demodulating the VHF intermediate frequency signal output from the VHF processing unit and the UHF intermediate frequency signal output from the UHF processing unit. Therefore, a manufacturing cost may be reduced, switching loss may be prevented.

Abstract: A power reduction proposal for a receiver circuit that adheres to a plurality of defined states and masking logic to mask the output of the squelch receiver. Furthermore, the proposal utilizes and counters to count the various timeout conditions. Consequently, the squelch receiver consumes less power and can be either powered down or periodically enabled to allow for polling.

Abstract: According to one embodiment, an input control unit to provide isolation and electrostatic discharge (ESD) protection for a circuit in an RF transceiver comprises a switching device coupled between an input of the circuit and ground. The switching device is configured to provide ESD protection while the circuit is activated. The switching device is further configured to ground the input while the circuit is non-activated, thereby concurrently isolating the input and providing ESD protection. A method for providing isolation and ESD protection for a circuit in an RF transceiver comprises activating the circuit, providing ESD protection while the circuit is activated, deactivating the circuit, and coupling an input of the circuit to ground, thereby concurrently isolating the input and providing ESD protection while the circuit is non-activated. The method and switching device can be used to provide isolation and ESD protection to receive bands in the RF transceiver.

Abstract: Communication is provided which includes receiving a transmitted radio signal at a powerline wherein the powerline functions as a receiving antenna for the wirelessly transmitted radio signal. The powerline is coupled to an input of a radio receiver using a coupler to communicate the radio signal to the radio receiver. For calibration purposes a second antenna not coupled to powerline may be used. A method for powerline communication across transformers, open circuit breakers, and other devices is also provided. In addition, a method of monitoring a device connected to a powerline is provided.

Abstract: A vanadium dioxide front-end advanced shutter device. The electronic shutter device is designed to protect receiver front-ends and other sensitive circuits from HPM pulse events such as HPM weapons, directed energy weapons, or EMPs. The shutter incorporates a transition material such as thin-film vanadium oxide (VOX) materials that exhibit a dramatic change in resistivity as their temperature is varied over a narrow range near a known critical temperature. A high-energy pulse causes ohmic heating in the shutter device, resulting in a state change in the VOX material when the critical temperature is exceeded. During the state change the VOX material transitions from an insulating state (high resistance) to a reflective state (low resistance). In the insulating state, the shutter device transmits the majority of the signal. In the reflective state, most of the signal is reflected and prevented from passing into electronics on the output side of the shutter device.

Abstract: Provided are a broadcasting receiving apparatus and a broadcasting receiving method using the same. The broadcasting receiving apparatus including: a low noise amplifying unit low-noise-amplifying an RF signal received from an antenna; an RF attenuating unit attenuating the received RF signal to output the attenuated RF signal; a supply unit supplying a DC voltage to the low noise amplifying unit; and a control unit controlling an output of the DC voltage depending on a change of an electric field strength of the received signal.

Abstract: Circuitry includes a voltage-controlled switch having a transmitter input, a receiver input, and an output that connects to one of the transmitter input and the receiver input. Passive components form a low-pass filter that is electrically connected to the transmitter input. The passive components are part of a multilayer ceramic passive module that includes a base body made of superimposed dielectric layers and electrically conductive layers. The voltage-controlled switch is on an upper portion or a lower portion of the base body.

Abstract: Structurally simple transmit/receive circuits for hearing devices are to be able to be deployed for higher frequencies as well. It is therefore proposed according to the invention that at least two PIN diodes should be connected in an anti-parallel manner between the receive oscillating circuit and the amplifier connected thereto to protect the amplifier. A capacitance diode can optionally be expanded so that larger component tolerances can be permitted for the circuit.

Abstract: The radio frequency integrated circuit (RFIC) electrostatic discharge (ESD) circuit includes an integrated circuit pad and a radio frequency (RF) ESD circuit. The integrated circuit pad provides coupling to an antenna. The RF ESD circuit is coupled to the integrated circuit pad, wherein the RF ESD circuit provides ESD protection at the integrated circuit pad, provides coupling of inbound RF signals from the antenna to low noise amplifier, and provides coupling of outbound RF signals from a power amplifier to the antenna.

Abstract: An electrostatic-discharge/impedance-matching circuit for use in radio frequency (RF) integrated circuits. The electrostatic-discharge/impedance-matching circuit comprises at least one shunt circuit operable to shunt current related to an over-voltage condition and at least one series element operably coupled to the shunt element. The shunt element and series element in combination provide electrostatic discharge protection for the RF signal processing circuit elements on the integrated circuit and also provide a matched input impedance for an incoming RF signal. Various alternate embodiments of the electrostatic-discharge/impedance-matching circuit include first and second shunt elements and a series element operably connected in combination to provide optimal electrostatic discharge protection and impedance matching.

Abstract: An embodiment is a receiver for a communications system that may substantially block unwanted signals in a frequency range to protect the receiver from overload. Simultaneously, the receiver of an embodiment substantially passes a desired signal so that its information may be processed by the, for example, communications system of which the receiver is part.

Abstract: An apparatus and method for internally calibrating a direct conversion receiver (DCR) through feeding a calibration signal via ESD protection circuitry is disclosed. The apparatus includes an internal signal generator for generating a calibration signal, a front-end input stage for receiving an RF signal at an input node, an ESD protection unit for protecting against electrostatic discharge, and a switch unit coupled to the ESD protection unit, for selectively passing a calibration signal to the front-end input stage, whereby the connection of the switch unit and the ESD protection unit means that when the DCR is operating in normal mode, the switch unit will not affect the noise performance and matching of the receiver.

Abstract: Provided is a method for protecting user data in a PDA telephone having functions of a PDA and a telephone. The method includes checking a voltage of the PDA telephone through a first low voltage sensor when both the PDA and the telephone are in OFF states and prohibiting user's manipulation on the PDA telephone when the voltage of the PDA telephone goes to a first low voltage.

Abstract: An SW control circuit turns ON and OFF a switch circuit provided between a reception antenna and an RF amplifier circuit, based on a noise removal control signal which is generated by a timing generation circuit and has a constant pulse width and a constant pulse interval, and thus the antenna is periodically short-circuited. In this way, even when the antenna receives a signal mixed with noise signals, accumulated energy due to the noise signals is periodically released, and thus the noise signals can be removed from the reception signal, and long lasting influence caused by the accumulated energy of the noise signals can be also removed.

Abstract: Local oscillator apparatus comprising communication signal terminals for a communication signal, especially in a receiver or a transmitter, and a controlled frequency oscillator for producing a local oscillator signal. The local oscillator also includes a reference frequency generator and a feedback loop for selecting and adjusting the frequency of the local oscillator signal relative to the frequency of said reference frequency signal. A first frequency divider divides the frequency of the local oscillator signal by a first division factor to produce a conversion signal, where the frequency of said conversion signal is at least approximately equal to the frequency of the communication signal, and conversion means responsive to the conversion signal converts between said communication signal and base-band signal.

Abstract: An embodiment is a receiver for a communications system that may substantially block unwanted signals in a frequency range to protect the receiver from overload. Simultaneously, the receiver of an embodiment substantially passes a desired signal so that its information may be processed by the, for example, communications system of which the receiver is part.

Abstract: Structurally simple transmit/receive circuits for hearing devices are to be able to be deployed for higher frequencies as well. It is therefore proposed according to the invention that at least two PIN diodes should be connected in an anti-parallel manner between the receive oscillating circuit and the amplifier connected thereto to protect the amplifier. A capacitance diode can optionally be expanded so that larger component tolerances can be permitted for the circuit.

Abstract: A receiver protection circuit in a time-division duplex (TDD) system is disclosed, which comprises a first diode with an anode coupled to an input of a low-noise-amplifier (LNA) and a cathode coupled to a ground (GND), a controller coupled to the anode of the diode and configured to generate a first control signal for turning on the diode when the TDD system is in a transmission mode, and a load coupled to the diode, wherein a reflected transmit signal is shorted to the GND by the diode and the radio frequency (RF) energy carried in the reflected transmit signal is consumed by the load.

Abstract: An integrated circuit comprises an ESD protection circuit including an inductor coupled between an input terminal and a ground terminal at which an RF signal is applied. The inductor is designed so as to provide a sufficient current capability required in typical ESD events. Moreover, the inductance of the inductor is selected to define, in combination with any parasitic capacitance present, a resonance tank with a resonant frequency that is matched to the RF signal. Accordingly, the operating frequency of the integrated circuit is not limited by the ESD protection circuit. In a further embodiment, an output terminal is ESD protected by an inductor that is coupled to an auxiliary voltage serving to bias an output transistor. Moreover, clamping elements, such as diodes, are provided between the auxiliary voltage and the supply voltage and between the auxiliary voltage and ground potential.

Abstract: An electrostatic-discharge/impedance-matching circuit for use in radio frequency (RF) integrated circuits. The electrostatic-discharge/impedance-matching circuit includes at least one shunt circuit operable to shunt current related to an over-voltage condition and at least one series element operably coupled to the shunt element. The shunt element and series element in combination provide electrostatic discharge protection for the RF signal processing circuit elements on the integrated circuit and also provide a matched input impedance for an incoming RF signal. Various alternate embodiments of die electrostatic-discharge/impedance-matching circuit include first and second shunt elements and a series element operably connected in combination to provide optimal electrostatic discharge protection and impedance matching.

Abstract: A radio receiver disclosed is composed of a signal processing part, which includes a receive band pass filter 2 and a receive low noise amplifier 3, to process receive signal and discharge gas with time, the signal processing part being cooled by the cooling means 6, wherein the radio receiver is provided with an airtight container 10 that operates as inner sealing means to seal the receive band pass filter 2 and the receive low noise amplifier 3 to retain the gas, and a vacuum container 5 that operates as outer sealing means to seal in vacuum the airtight container 10 such that an interspace 12 between that and the airtight container 10 forms a vacuum insulating space to insulate in vacuum the airtight container 10 from outside.

Abstract: An antenna detection and diagnostic system and associated method, including current and voltage detection circuits, are disclosed for detecting antenna failure mechanisms for integrated radio receivers. Integrated current limit detection circuitry is disclosed that determines current levels drawn by a remotely mounted antenna and generates a drive signal that controls a current limiting pass transistor such that current flow through the transistor is reduced when the detected current level drawn antenna rises above a current limit level. Integrated current and voltage detection circuitry is disclosed that detects current and voltage levels drawn by a remotely mounted antenna and determines under-current, over-current, and over-voltage antenna error conditions. At least one antenna error output pin for the integrated radio receiver is then used provide an output signal indicative of antenna error conditions.

Abstract: A receiver device for receiving incoming radio waves by using a plurality of antennas, which is capable of improving the maximum input sensitivity is provided. In the receiver device, a switching unit switches to an antenna having the lower antenna gain as a new receiving antenna on the precondition that when receiving incoming radio waves by one particular antenna currently set as the receiving antenna, if a reception level of this particular antenna becomes a level close to the maximum input sensitivity of a signal processing unit, then the reception condition is satisfactory. Consequently, it is possible to improve the maximum input sensitivity and forestall the occurrence of waveform distortion and the like.

Abstract: A receiver and a composite component for preventing noise produced by sneaking of a local oscillation signal. An FM receiver comprises a high-frequency amplifier circuit 11, a mixing circuit 12, a local oscillator 13, intermediate-frequency filters 14 and 16, an intermediate-frequency amplifier circuit 15, a limit circuit 17, an FM detection circuit 18, and a stereo demodulation circuit 19. The mixing circuit 12 and the local oscillator 13 constitute a one-chip composite component 30 integrally formed on a semiconductor substrate. The frequency of the local oscillation signal is set so that the difference of frequency between the local oscillation signal and a modulated wave signal may be smaller than the occupied bandwidth of the modulated wave signal.

Abstract: The present invention relates to systems and methods that employ a novel balanced duplexer that can be utilized to facilitate concurrent signal transmission and reception. The systems and methods can be employed within mobile devices such as cell phones and utilize two-filters (e.g., acoustic) with substantially similar input/output impedances interfaced with two couplers (e.g., 3 dB hybrid), which provide isolation and maintain the duplexer's input/output impedance. The couplers interface the filters to front/back ends such as signal processors, transmitters and receivers. The novel aspects of the present invention mitigate the need to employ external directional couplers between the duplexer and front/back ends. In addition, the two-filter topology enables employment of lower powered rated filters. The systems and methods further provide for separation and isolation of transmitters and receivers, which reduces noise coupling and enables the transmitter and receiver to be placed within close proximity.

Abstract: A single chip direct conversion transceiver that includes a substrate on which a mixer unit and a local oscillator are provided as a circuit, and a positive hole formed between the mixer unit and the local oscillator and filled with a conductive plug to block signal leakage. A shield ground surface is formed above the substrate and blocks signal leakage occurring when the signals received through the antenna are input into the mixer and signal leakage occurring when the reference signal is input into the mixer from the local oscillator. A first interconnection is formed above the shield ground surface and connects the mixer unit and the local oscillator. Dielectric layers are formed between the substrate and the shield ground surface and on the shield ground surface to cover the first interconnection.

Abstract: A receiver method and apparatus is presented. Signals are received from a high-voltage environment to a low-voltage environment using low-voltage devices, such as low-voltage FETs. A reference stage (i.e., first stage) provides the reference point for an input signal that is received into a second stage. The reference stage works in conjunction with the second stage to control the output of the second stage. The reference stage and the second stage communicate through floating voltage signals. The output of the second stage is an inverted signal that floats. A third stage receives the inverted signals and corrects the signal to a baseline (i.e., adds gain to the signal). The signal is then clipped by a clipping stage (i.e., fourth stage). The clipping stage clips the high-voltage signal so that it will operate with the devices in the low-voltage environment. A fifth stage is then biased with a low voltage and the clipped signal is shifted downwards. Lastly, an inverter (i.e.

Abstract: An apparatus and method for switching a GPRS (General Packet Radio Service) service class according to the heat generated by at least one specific element in a GPRS terminal during a GPRS mode of operation. A temperature sensor measures a temperature of a specific element in the GPRS terminal during a GPRS mode of operation. An A/D converter converts an analog value of the temperature measured by the temperature sensor to a digital value. A limit data register stores a critical temperature of the specific element for the GPRS service class. A controller compares the measured temperature from the temperature sensor with the critical temperature stored in the limit data register, and switches the GPRS service class to a low class, when the measured temperature is greater than or equal to the critical temperature. The controller maintains the present GPRS service class when the measured temperature is less than the critical temperature.

Abstract: A single chip RF communication system and method is provided including a transmitter and a receiver. The RF communication system in accordance with the present invention can include an antenna that receives/transmits RF signals, a PLL that generates multi-phase clock signals having a frequency different from a carrier frequency and a reference signal having the carrier frequency, a demodulation-mixer that mixes the received RF signals with the multi-phase clock signals having the frequency different from the carrier frequency to output signals having a frequency reduced relative to the carrier frequency, two stage amplification that amplifies a selected channel signal to a required dynamic level, and an A/D converting unit for converting the RF signals from the mixing unit into digital signals. The two stage amplification can provide the selected channel signal with sufficient gain, even when an adjacent channel signal is output by the demodulation mixer with greater amplitude or power.

Abstract: A HTS-based RF receiver includes a cryocooler and a cryogenic enclosure in thermal communication with the cryocooler. The cryogenic enclosure contains a HTS filter and a LNA therein. A first MEMS bypass switch is positioned between a RF input and the HTS filter, the first MEMS bypass switch operatively coupling the RF input to the HTS filter. A second MEMS bypass switch is positioned between the LNA and RF output, the second MEMS bypass switch operatively coupling the LNA to the RF output. A bypass pathway located within the cryogenic enclosure is connected between the first and second MEMS switches to bypass the HTS filter and LNA when an operating parameter of the RF receiver falls outside a pre-determined range.

Abstract: An apparatus and method for radio signal parallel processing are provided, wherein the apparatus, which receives and processes in parallel a first and second carrier signal of frequencies &ohgr;1 and &ohgr;2 (&ohgr;2>&ohgr;1), includes: a first local oscillator which outputs a signal of frequency &ohgr; to a first frequency mixer which converts the first carrier signal into a signal of a first intermediate frequency (&ohgr;−&ohgr;1) and a signal of another first intermediate frequency (&ohgr;+&ohgr;1), and outputs the converted signals; and a second frequency mixer which converts the second carrier signal into a signal of a first intermediate frequency (&ohgr;2−&ohgr;) and a signal of another first intermediate frequency (&ohgr;2+&ohgr;), and outputs the converted signals. With the above, the capacity of data reception and transmission increases, the complexity of implementing the apparatus is low, and the cost of manufacturing the apparatus is reduced.

Abstract: An RF device has a substrate, a field effect transistor formed on the principal surface of the substrate, a grounded conductor film formed on the back surface of the substrate opposite to the principal surface, and a protective circuit formed between the gate of the field effect transistor and the grounded conductor film. The protective circuit is composed of an inductor or an inductor and a capacitor connected in parallel to each other.

Abstract: A receiver for rejecting an image signal is provided that does not require a phase-shifter and that requires less mixers than prior receivers. Thus, the phase imbalances and gain mismatches imparted by phase shifters are avoided, and harmonics due to non-liner effects in the mixers are reduced.

Abstract: The present invention relates to a novel use of cryoelectronic equipment to implement an extremely sensitive and stable receiver front end for UHF, microwave, and millimeter wave applications. The invention is particularly applicable to base station receivers in mobile radio systems, where the range and capacity of the systems are typically limited by the base station receiver sensitivity.

Abstract: An air cooled transceiver enclosure which includes multiple cooling posts about the enclosure. The transmitter and receiver antennas are planar mounted above the cooling posts and the cooling posts are selected so as not to interfere with the radiation and form part of the ground plane. The cooling posts are, in general, of a height which is less than one-quarter the wave length of the frequencies to be used. In accordance with another feature of the present invention, the transceiver base unit with cooling posts and mounted antennas has an easily attachable cover which is removably engaged to the transceiver base unit and offset from the planar antennas which lie above the base unit. In accordance with another feature of the invention, the transceiver base unit with cooling posts and mounted antennas has an easily attachable cover which is removably engaged to the transceiver base unit and offset from the planer antennas which lie above the base unit.

Abstract: A window glass antenna system for the reception of AM and FM radio broadcasts in an automobile includes an antenna grid applied to a window of a vehicle, that is electrically separate from a heater grid applied to the rear window. An antenna module connected to the vehicle window antenna grid is comprised of a low noise amplifier, matching, and overload protection circuits. The overload protection circuit is included between the antenna grid and the RF amplifier. When the received radio antenna signal is at the typical operating level of the amplifier, the overload protection circuit connects the output of the antenna grid to the RF amplifier. When the received signal is higher than the linear dynamic range of the amplifier the overload protection circuit provides linearity of the signal that is applied to the car radio. This process consists of two steps.

Abstract: A direct conversion transceiver capable of reducing a DC offset, using a multi-chip module is provided. In the transceiver, a mixer and an element constituting a local oscillator are positioned above a shielding ground surface, and an interconnection connecting the mixer and the element constituting the local oscillator are positioned below the shielding ground surface. The transceiver is formed as a multi-chip module and thus its size is not bigger than a one-chip direct conversion receiver and advantageous in that its size and manufacturing costs are less than a general direct conversion receiver that additionally includes a DC offset cancellation circuit or an off-chip type oscillator for reducing a DC offset.

Abstract: A satellite receiving converter of the present invention performs receiving operation in response to a pulse signal supplied from a tuner. To prevent an amplitude of the pulse signal from being largely reduced in the receiving operation, the satellite receiving converter includes a trap circuit made up of an inductor and a capacitor. The trap circuit is provided after a low-pass filter which divides a pulse signal and a direct-current voltage supplied to a regulator IC. The trap circuit is provided so as to raise impedance with respect to the pulse signal at a signal input-output terminal, thereby preventing error operation of an internal circuit, such as a control circuit.