Abstract: A communication system, for providing services to a plurality of subscribers, comprises a network controller, a base station, and a wireless mobile subscriber unit. The network controller includes a memory for storing a plurality of memory templates. Each memory template contains information pertaining to a subscriber. A controller processes information in the memory templates. A transceiver transmits information from the memory templates to subscribers upon request by a subscriber and at times automatically determined by the network controller. A general services tank provides general services to the subscribers, and an individual services tank provides individual services to the subscribers. The base stations each include a radio transceiver that includes a memory, coupled to the radio transceiver, for storing a plurality of memory templates.

Abstract: In a radio transceiver (11) including a voltage controlled oscillator (VCO) (24) having an output for coupling to a switchable load (32, 30), a switch (42) couples a compensating load (44) to the output of the VCO when the switchable load is in an off state. The compensating load has an impedance that compensates for the decoupling of the load impedance from the output of the VCO, thus avoiding frequency pull problems. In a further aspect of the invention a voltage variable capacitor (100) is used as the switch.

Abstract: A code division multiple access (CDMA) communication system (10) for reuse of available spreading codes includes a first communication device (100) and a second communication device (106). The first and second communication devices (100, 106) are capable of identifying spreading codes and operating frequencies that are optimum for their respective radios. The identity of the optimum spreading code and the frequency of the optimum frequency is communicated from one communication device (100) to another (106), hence allowing the two devices to communicate with each other using their respective optimum codes and frequencies. These codes and frequencies may be periodically updated to provide reusability of codes. By dynamically updating codes and frequencies without the use of a central station, the efficiency and reusability of codes in the CDMA system (10) is significantly enhanced.

Abstract: A bandpass filter, having an input port and an output port, comprises a first microstrip split-ring resonator coupled to input port, and a second microstrip split-ring resonator coupled to the first microstrip split-ring resonator, and coupled to the output port. A lumped or distributed capacitance is disposed between the first microstrip split-ring resonator and the second microstrip split-ring resonator.

Abstract: A squelch circuit (200) having an input is provided including a programmable high pass filter (206) for filtering the input signal to produce a filtered signal. The filtered signal is rectified via a differential rectifier (201) to produce a rectified signal. The squelch circuit (200) also includes a threshold comparator (323) coupled to the differential rectifier (201) for sensing when the rectified signal exceeds a squelch threshold.

Abstract: An integrated-distributed-inductive-capacitive network (100) having a high dielectric electronically-tunable semiconductor integrated capacitor. The network (100) also includes a conductive layer (126) formed on the high dielectric semiconductor integrated capacitor, to provide the distributed resistance of the network (100). External contact to the network (100) is provided via a plurality of contact terminals (122A and 122B) which are coupled to the conductive layer (126).

Abstract: An electronic device (100) includes a substantially planar housing (110). The housing (110) includes a portion (104) being selectively rotatable out of the plane of the housing (110). The electronic device (100) includes an electronic circuit (400) placed in the housing (110). The electronic device (100) further includes a switch (114, 116, and 118) coupled to the rotatable portion (104) of the housing (110).

Abstract: A radio-frequency amplifier (50) has an impedance transformation network (66) with a control input (70) for controlling the transformation characteristic of the transformation network (66). The radio-frequency amplifier (50) amplifies an input signal to produce an amplified radio-frequency output signal to a load (68). The control circuit selects a power level for the output signal, in response to a control signal, by transforming the impedance of the load to a transformed impedance at the output of the radio-frequency amplifier, so that the efficiency of the radio-frequency amplifier is not substantially degraded as the power level for the output signal is changed.

Abstract: Briefly, according to the invention, a noise-cancelling microphone apparatus 302 is disclosed. The microphone comprises a housing 510 and a sound transducer 502 mounted within the housing 510. The housing has first 514 and second sides 512 and the transducer 502 has first 304 and second sound ports 308 coupled to the first 514 and second sides 512 of the housing respectively. The microphone 302 also includes a mounting clip 310 coupled to one side of the housing 512 in the proximity of one of the sound ports 308. The mounting clip 310 is intended for mounting the microphone 302 to a user so as to substantially close the sound port 308 when microphone 302 is attached.

Abstract: Briefly, according to the invention, a multi-unit communication device having a transceiver unit 108 and a control unit 104 is provided. The transceiver unit 108 transmits and receives information signals having digital and analog portions. The control unit 104 provides for operator interface to the communication device. The communication between the transceiver unit 108 and the control unit 104 is conducted on a single pair of wires 112 using ISDN format.

Abstract: A communication system 100 comprising a dispatch sub-system 100A, a plurality of transmitters 100B, and a plurality of mobile transceivers 100C is disclosed. An antenna coupler 410 and a location sensor 414 are coupled to one another via a coax cable 412. The bias current to the coupler is supplied by the location sensor 414 via the resistor 406. A detector 200 measures the voltage across the resistor 406 which is relative to the current flowing in to the antenna coupler 410. The detector 200 compares the measured voltage via comparators 218 and 238 and determines if the measured voltage is beyond a certain boundary. The NOR gate 244 routes the comparison result to a MPU 250. The MPU 250 processes the result and transmits a signal to a base station 104 via the mobile transceiver 118. The base station 104 decodes the received signal and presents it to a dispatch center 106.

Abstract: Briefly, according to the invention, a microphone apparatus (100) for converting sound waves to electrical signals is described. The microphone apparatus (100) includes a switch (118) for initiating the occurrence of an event. The switch (118) being substantially covered by a cap (102). The microphone apparatus (100) also includes a microphone port (114) disposed substantially behind the cap (102), thus minimizing the obstruction of the microphone port (114).

Abstract: An amplitude modulator circuit, having an input for receiving an input information signal and an output for providing an output signal, which is proportional to the input signal. The amplitude modulator circuit comprises at least two pass devices for amplifying the input information signal to produce the output signal and applying it to a load. The amplitude modulator circuit further comprises at least two voltage supplies for applying a plurality of supply voltages (at least some of which have different voltages) to the pass devices. The amplitude modulator circuit also includes a driver circuit having an input for receiving the input signal, and at least two driver outputs for driving the pass devices. The driver circuit activates the pass device having the lowest supply voltage that is sufficient to supply the required voltage to the load.

Abstract: An oscillator circuit (200) is provided having a crystal oscillator (202) operating in a first oscillator mode to produce an oscillator output signal (201). The oscillator output signal (201) has a desired frequency of operation. The oscillator circuit (200) also includes switches (206A and 206B) for selectively forcing the crystal oscillator (202) to operate in a second oscillator mode in order to shift the frequency of the oscillator output signal (201).

Abstract: A method for redirecting calls to a cordless telephone wherein the user of the cordless telephone registers a location code at a call redirecting module. The location code informs the call redirecting module to redirect calls, that are directed to a first telephone unit, to a base station which is part of a network. The base station transmits the call, so that the cordless telephone receives the call if it is within the range of the base station. In the event that the cordless telephone receives the call, it transmits an acknowledgement signal. The base unit will cease to transmit the call if it does not detect the acknowledge signal within a predetermined time interval.

Abstract: An electronic device (100) having a battery (116) with an associated battery voltage. The battery (116) includes a plurality of cells configured to form a plurality of battery portions (116A and 116B). The electronic device (100) also includes a regulator (102), a first circuit (118), and a swith control circuit (106). The regulator (102) operates on the battery voltage and produces a regulated voltage. The first circuit (118) operated on the battery voltage. The switch control circuit (106) alternately applies the regulated voltage to the plurality of battery portions (116A and 116B) so as to charge the battery (116).

Abstract: A multipurpose light apparatus (100) is described for use with an electronic device (400) for indicating the occurrence of an event and providing a programming path for the electronic device (400). The light apparatus (100) includes an indicator light source (104) for indicating the occurrence of an event and a light adapter (102) having a plurality of terminals. One of the terminals (112) of the light adapter (102) is coupled to the indicator light source (104). The light apparatus (100) also includes a light sensitive detector (108) coupled to a second terminals (114) of the light adapter (102). The light sensitive detector (108) provides the means for receiving information to program the electronic device (400).

Abstract: A radio frequency variable gain amplifier (204) has a plurality of outputs. The amplifier (204) includes a transistor amplifier (330) having a plurality of switchable fixed gain states for amplifying an oscillator signal. The amplifier (204) includes a biasing circuit (302, 306, 312, and 316) for selectively biasing the transistor amplifier (330) to produce the plurality of switchable fixed gain states. The biasing circuit (302, 306, 312, and 316) includes switches (310 and 320) for switching between the switchable fixed gain states of the transistor amplifier (330).

Abstract: An integrated-distributed-resistive-capacitive network (100) having a high dielectric electronically-tunable semiconductor integrated capacitor. The network (100) also includes a resistive layer (126) formed on the high dielectric semiconductor integrated capacitor, to provide the distributed resistance of the network (100). External contact to the resistive portion of the network (100) is provided via a plurality of contact terminals (122A and 122B) which are coupled to the resistive layer (126).