Abstract: A low-profile antenna for operating in the 800 to 900 mHz range and especially suited for use with portable, hand-held electronic apparatus. The antenna features printed circuit board construction for precision fabrication, broadband operations and enhanced efficiency. The antenna includes a driven element in close association with a parasitic element printed on one surface of the printed circuit board in a side-by-side, parallel relation. A conductive strip is included on the other side of the board spanning the free ends of the driven and parasitic elements to enhance the coupling therebetween.

Abstract: Method and apparatus for communicating credit card information read at a mobile radiotelephone unit is disclosed. Data read from a credit card is placed in a variable length error protected format and transmitted from the mobile radiotelephone unit to authorize payment of the radiotelephone call.

Abstract: An battery powered, adaptive signal decoder is disclosed which is capable of processing detected encoded signals in accordance with a plurality of decoding schemes. The decoder has an equivalent microcomputer implementation. Energy conservation means operating independently of the detected signals acts to conserve the energy of the battery.

Abstract: An acknowledge back (ack-back) pager is provided for receiving paging signals from a central paging station. The central paging station transmits a group of message signals to a group of ack-back pagers which are addressed as a group. The users of the group of addressed ack-back pagers indicate a response to their respective pagers thus providing ack-back data. The pagers in the group of addressed ack-back pagers then simultaneously transmit back to the central station their ack-back data on different frequency sub-bands, a different frequency sub-band being dynamically allocated to each of the pagers in the group. Each ack-back pager determines whether the paging signals received thereby exhibits a signal level less than a predetermined threshold level. If the paging signals received by a particular ack-back pager exhibit a signal level less than such predetermined threshold level, then the pager transmits back to the central station at a first output power level.

Abstract: A spring clip arrangement is disclosed for a portable battery powered device which provides an efficient chassis retention feature for a slideably removable electrical chassis in unassociated housing. This retention is accomplished without machine screws and no special tools required. This spring clip arrangement also serves as the electrical contact interface for the associated battery power source insertable in a provided battery compartment.

Abstract: An improved communication system is disclosed wherein at least one reprogramming station is added to a communication system. The reprogramming station is constructed and arranged to communicate with the subscriber units thereby either reprogramming or regrouping them. The subscribing units receive the reprogramming command and acknowledge individually, altering a memory means until either reprogrammed back to the original state, or to another state. In another mode, the reprogramming station transmits a regrouping command wherein two or more groups are combined to form a super group.

Abstract: A linear microwave attenuator has an absorbing element which is selectively shaped to provide reduced capacitive coupling and increased attenuation by segmenting the absorber into at least two members. The selective shaping reduces both the surface area and mass of the absorber while maximizing the attenuation of possible from the absorber. In this way, reduced size, linear performance, and increased attenuation over those of the prior art are provided by the present invention.

Abstract: An antenna tuning arrangement is provided for a miniature personal communications device which is normally worn on the body. The device includes a wristband having an antenna and antenna tuning elements which are normally concealed, to allow the antenna to be tuned while the device is being worn. A receiver in the communications device is coupled to the antenna and to a tuning indicator circuit which provides a tuning indication when the tuning element is adjusted without requiring entry into the device. The tuning indicator operation is selectable and draws no power when not selected.

Abstract: Apparatus and method is disclosed for automatically, or by selective response, call forwarding a message to one or more system pagers which have an acknowledge back capability.In one embodiment, disclosed apparatus automatically forwards a message to another system pager upon the initially called pager failing to acknowledge back within a predetermined time period. Such other pager is determined from a set paging hierarchy included within the paging terminal apparatus itself.In another embodiment, wherein the system pagers have multiple acknowledge back response capability, a called pager can request the received message be additionally call forwarded to one or more other system pagers in accordance with the particular acknowledge back response chosen by the called pager user.

Abstract: A small closed loop antenna is formed by a flat metal member formed into a U-shape which also serves as the front, back and top surfaces, or parts thereof, of the housing for a portable communications receiver. Connected to the open (bottom) end of the arms is an isolation network providing an optimum antenna ground and a reactance network which applies a capacitive reactance across the antenna and isolation network so that the conductive member forms an antenna that detects the H-field of the electromagnetic wave to be received. The reactance network is tunable to adjust the antenna for reception at particular frequencies.

Abstract: An antenna having provision for mounting to a printed circuit board and method for making the antenna is described. The antenna includes a generally elongate, magnetically permeable core having a major axis and an insulating substrate affixed along an axis parallel to the major axis. The insulating substrate has a plurality of opposed pairs of spaced conductive runners positioned at generally regular intervals along the substrate normal to the major axis. A plurality of discrete capacitors are and perpendicular to secured between the opposed pairs of conductive runners. An electrically conductive split sleeve substantially surrounds the core and has pairs of opposed tabs on the edge portions in electrical connection with the opposed pairs of conductive runners. The sleeve further includes integral mounting tabs for securing the antenna assembly to the printed circuit board to establish electrical connection to the antenna without the use of wire leads.

Abstract: A paging system is provided having page transmission means responsive to a message origination device for transmitting selective call paging signals and messages. A query signal is also transmitted a predetermined minimum time period from the corresponding paging signal. A plurality of transceivers are provided responsive to the selective call paging signals and messages, and further responsive to the query signals for enabling the generating and transmitting of a response signal. Receivers are provided for receiving the transmitted response signals. The received response signals are then delivered to the message origination device from which the original message originated.

Abstract: A paging system providing an LPC encoded speech output having an adaptive bit rate. The LPC bit rate is adaptively modified based on paging system airtime loading. Synthesizer circuitry in the paging receivers, together with a system signaling scheme is used to update the paging receivers as to the LPC bit rate, allows the paging receiver to decode the adaptive bit rate signal.

Abstract: A system transmitting synchronization signals and coded message signals is described. In particular, coded synchronization signals are used to indicate the transmission of coded message signals or the absence of transmission of coded message signals following the transmission of the coded synchronization signal, thereby providing a battery saving function for a personal communications receiver.

Abstract: A method and means for maintaining continuous bit synchronization of data transmitted from a remote unit through a base unit to a landline unit is disclosed. An input data stream at a first bit rate, such as digitized or encrypted speech, is interleaved with a plurality of signalling words, and transmitted over an RF channel at a second bit rate. The base site recovers the clock of the received data, strips off the signalling word, modifies the bit rate of the received data, and adjusts the recovered clock rate to provide an output data stream which is in bit synchronization with the input data stream and within a predetermined modem specification. The encrypted data is then sent over landlines to a decryption unit which requires bit synchronization.

Abstract: A wrist worn device includes a digital watch circuit and a receiver circuit which responds to coded message signals including selective call signalling and message information. An input steering circuit interfaces between the watch circuit and the receiver circuit for normally providing control of the watch circuit by switches located in the device case. The normal watch functions of the switches are permanently marked on the device case. The watch circuit and the receiver circuit couple to an information selector circuit which normally selects the watch output for a common display. When coded message signals are received, the switches are enabled to control the receiver circuit, and the received message information is selected for display. New indicia, electronically selected by the information selector circuit, are displayed on the display defining the new functions of the switches.

Abstract: A flexible circuit interconnect system and method for providing direct electrical contact between a flexible circuit and a printed circuit board or an additional flex circuit is disclosed. In one embodiment, elastomeric material is located between the flex circuit and a rigid support to provide an interconnection receptacle for electrical contact with a printed circuit board. In another embodiment, one flex circuit surrounds a formed elastomeric wedge and a second flex circuit is rigidly supported with an opening corresponding to the wedge. Compression of elastomeric material maintains direct contact between the connecting pads of the circuit members.