Patents Assigned to Silcom Research Limited
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Patent number: 6233431Abstract: The present invention relates to a radio receiver for receiving a radio signal, a first circuit for beating the signal to zero intermediate frequency in phase and quadrature shifted signals, a circuit for amplifying the in phase and quadrature shifted zero intermediate frequency signals, a second circuit for beating the amplified intermediate frequency signals to predetermined non-zero intermediate frequency in phase and quadrature shifted signals, a summer for summing the non-zero signals, and a circuit for applying the summed signals to a discriminator to obtain an output signal. Other embodiments are extended POCSAG for enhanced battery saving, paging sequence numbers for reception integrity control, digital AFC, script control of the pager for organizer/schedule applications, a vibrator holster for improved pager format and saving of battery power, intelligent low battery detection, and features arising from electronic on/off function.Type: GrantFiled: August 18, 1993Date of Patent: May 15, 2001Assignee: Silcom Research LimitedInventors: Gyles Panther, J. Peter Williams
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Patent number: 5812617Abstract: A synchronization apparatus in a selective call receiver comprised of a digital variable bandwidth phase locked loop with means to simultaneously detect the synchronization code word, means to generate a binary code from a register representative of lock quality, means to increment or decrement the lock quality register, means to sum the lock quality binary code into a phase error register, whereby the polarity of the sum is controlled by a phase comparison of the a local clock with the received data, and whereby the under or over flow of the phase error register determines the direction of a phase adjustment to the local bit clock generator.Type: GrantFiled: December 28, 1994Date of Patent: September 22, 1998Assignee: Silcom Research LimitedInventors: John Benjamin Heckman, Gyles Panther
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Patent number: 5696437Abstract: A low battery condition is determined by sampling battery terminal voltage with a voltage comparator under light and heavy loading, and indicating a low battery condition when the rate of change of the sampled voltage or the rate of change of the internal resistance of the battery is greater than a predetermined limit.Type: GrantFiled: August 18, 1993Date of Patent: December 9, 1997Assignee: Silcom Research LimitedInventors: Gyles Panther, J. Peter Williams
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Patent number: 5642102Abstract: A holster for a radio pager contains an electrical element which can be detected by the matching radio pager when the pager is inserted into the holster. In one embodiment the pager and holster have matching electrical contacts which are made when the pager is inserted into the holster. The pager contains means to sense the connection of a specific impedance and to convey this data to an internal control device. The control device has the capability to alter the mode of alert from vibrate to an alternate alert mode such as audible alert, according to the pre-selected choice of the user, under control of the low impedance sense signal. The holster sense circuit output is also used by the control device to invert the orientation of displayed information, to provide for on-belt reading of a front faced display pager.Type: GrantFiled: March 20, 1995Date of Patent: June 24, 1997Assignee: Silcom Research LimitedInventors: Gyles Panther, J. Peter Williams
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Patent number: 5551079Abstract: A holster assembly for retaining a radio pager or data receiver including a clip fixed to the assembly having a first position for resiliently clamping the holster assembly to an article of clothing and another stable open position for supporting the assembly on a surface as a stand for the pager or receiver, a vibrator alert apparatus and a battery connected thereto contained wholly within a housing formed by the holster assembly.Type: GrantFiled: April 29, 1993Date of Patent: August 27, 1996Assignee: Silcom Research LimitedInventors: Gyles Panther, J. Peter Williams, Donald W. F. Campbell
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Patent number: 5263195Abstract: The present invention relates to a radio receiver for receiving a radio signal, a first circuit for beating the signal to zero intermediate frequency in phase and quadrature shifted signals, a circuit for amplifying the in phase and quadrature shifted zero intermediate frequency signals, a second circuit for beating the amplified intermediate frequency signals to predetermined non-zero intermediate frequency in phase and quadrature shifted signals, a summer for summing the non-zero signals, and a circuit for applying the summed signals to a discriminator to obtain an output signal. Other embodiments are extended POCSAG for enhanced battery saving, paging sequence numbers for reception integrity control, digital AFC, script control of the pager for organizer/schedule applications, a vibrator holster for improved pager format and saving of battery power, intelligent low battery detection, and features arising from electronic on/off function.Type: GrantFiled: March 28, 1991Date of Patent: November 16, 1993Assignee: Silcom Research LimitedInventors: Gyles Panther, J. Peter Williams
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Patent number: D348462Type: GrantFiled: May 11, 1992Date of Patent: July 5, 1994Assignee: Silcom Research LimitedInventor: David W. F. Campbell