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91. 发明专利

GB2310543B An antenna 未知
公开(公告)号：GB2310543B
公开(公告)日：1999-10-06
申请号：GB9703214
申请日：1997-02-17
申请人： SYMMETRICOM INC
发明人： LEISTEN OLIVER PAUL
IPC分类号： H01Q21/24 , H01Q1/38 , H01Q11/08 , H01Q1/36
摘要： An antenna for use at frequencies of 200MHz and upwards has a cylindrical ceramic core (12) with a relative dielectric constant of at least 5, and pairs of helical elements (10A - 10D) extending from a feed point at one end of the core (12) to the rim (20U) of a conductive sleeve (20) adjacent the other end of the core (12) the sleeve (20) acting as a trap for isolating from ground currents circulating in the helical elements (10A - 10D). To yield helical elements (10A - 10D) of different lengths, the sleeve rim (20U) follows a locus which deviates from a plane perpendicular to the core axis in that it describes a zig-zag path. The helical elements (10A - 10D) form simple helices with approximately balanced radiation resistances.

92. 发明专利

GB2326532B An antenna 未知
公开(公告)号：GB2326532B
公开(公告)日：1999-02-24
申请号：GB9821153
申请日：1995-08-21
申请人： SYMMETRICOM INC
发明人： LEISTEN OLIVER PAUL
IPC分类号： H01Q1/24 , H01Q1/38 , H01Q11/08

93. 发明专利

GB9821155D0 A radio telephone 未知
公开(公告)号：GB9821155D0
公开(公告)日：1998-11-25
申请号：GB9821155
申请日：1995-08-21
申请人： SYMMETRICOM INC
IPC分类号： H01Q1/24 , H01Q1/38 , H01Q11/08

94. 发明专利

GB9813002D0 An antenna 未知
公开(公告)号：GB9813002D0
公开(公告)日：1998-08-12
申请号：GB9813002
申请日：1998-06-16
申请人： SYMMETRICOM INC
IPC分类号： H01Q1/24 , H01Q1/36 , H01Q1/38 , H01Q5/00 , H01Q5/357 , H01Q11/08 , H04B1/38 , H04B1/3827
摘要： A dielectric-loaded antenna having a plurality of radiating elements and a loop element plated on the surface of a cylindrical ceramic core has balanced and single-ended modes of resonance which are coupled together so as to define an operating frequency band. The two modes of resonance are associated with different respective radio frequency current patterns in the radiating elements, and the input reactance component of the load represented by the antenna at its feedpoint is substantially zero within the operating frequency band only when the corresponding input resistance component is finite and substantially non-zero.

95. 发明专利

CA2272389A1 A DIELECTRIC-LOADED ANTENNA 未知
公开(公告)号：CA2272389A1
公开(公告)日：1998-06-04
申请号：CA2272389
申请日：1997-11-24
申请人： SYMMETRICOM INC
发明人： AGBORAW EBINOTAMBONG , LEISTEN OLIVER PAUL
IPC分类号： H01Q1/38 , H01Q1/24 , H01Q1/36 , H01Q5/00 , H01Q5/371 , H01Q11/08
摘要： A dielectric-loaded loop antenna for operation at frequencies above 200 MHz has an elongate cylindrical core with a relative dielectric constant greater than 5, a pair of co-extensive helical antenna elements, a coaxial feeder structure extending through the core from a proximal end to a distal end where it is coupled to the antenna elements, and a balum formed on the core cylindrical surface and connected to the feeder structure at the proximal end of the core. Each helical antenna element is bifurcated at an intermediate position so that proximally, it is formed of two generally parallel branches each of which is coupled to a respective linking path around the core to meet a corresponding branch of the other elongate element therefore forming a conductive loop between the two conductors of the feeder structure. The two conductive loops have different electrical lengths as a result of, for example, the branches being of differents lengths. In a preferred embodiment, the linking paths around the core are formed by the rim of a split conductive sleeve constituting the balum. The sleeve is formed in two parts separated by a pair of longitudinally extending diametrically opposed quarter wave slits each of which extends from the space between the branches of a respective helical antenna element to a short circuited end adjacent the proximal end of the core.

96. 发明专利

NO970832L 未知
公开(公告)号：NO970832L
公开(公告)日：1997-04-25
申请号：NO970832
申请日：1997-02-24
申请人： SYMMETRICOM INC
发明人： LEISTEN OLIVER PAUL
IPC分类号： H01Q1/40 , H01Q1/24 , H01Q1/36 , H01Q1/38 , H01Q11/08

97. 发明专利

GB9622798D0 Dielectric-loaded antenna 未知
公开(公告)号：GB9622798D0
公开(公告)日：1997-01-08
申请号：GB9622798
申请日：1996-11-01
申请人： SYMMETRICOM INC , COORS CERAMICS COMPANY
IPC分类号： H01Q1/36 , H01Q11/08

98. 发明专利

CA2220523A1 DIGITAL PHASE DETECTOR EMPLOYING A DIGITALLY CONTROLLABLE DELAY LINE 未知
公开(公告)号：CA2220523A1
公开(公告)日：1996-12-19
申请号：CA2220523
申请日：1996-06-05
申请人： SYMMETRICOM INC
发明人： MERRISS MORLEY M , ZAMPETTI GEORGE P , HAMILTON MICHAEL M
IPC分类号： H03L7/081 , H03L7/093 , G01R25/00
摘要： A digital phase detector composed of: a digitally controllable signal delay device having a signal input, a signal output and a control input, the delay device being operative for conducting a signal from the signal input to the signal output with a time delay having a duration determined by a control signal supplied to the control input, the signal input being connected to receive either an input signal or a digital local clock signal; a phase relation detector connected to receive a first input signal from the signal output of the signal delay device and a second input signal constituted by one of the input signal and the digital local clock signal which is not received by the signal input of the signal delay device, for periodically comparing the phases of the first and second input signals and for producing a binary output signal composed of a succession of signal segments, each segment having a first value when the first input signal is leading the second input signal in phase and a second value when the first input signal is lagging the second input signal in phase; and a digital modulator connected for receiving the binary output signal from the phase relation detector and producing a digital output representative of the magnitude of the phase difference between the input signal and the digital local clock signal based on the values of successive signal segments of the binary output signal produced by the phase relation detector.

99. 发明专利

GB9615917D0 An antenna system 未知
公开(公告)号：GB9615917D0
公开(公告)日：1996-09-11
申请号：GB9615917
申请日：1996-07-30
申请人： SYMMETRICOM INC
IPC分类号： H01Q11/12 , H01Q5/00 , H01Q5/357 , H01Q11/08
摘要： In an antenna system for radio signals in at least two spaced-apart frequency bands above 200 MHz, a quadrifilar helical antenna having an elongate dielectric core with a relative dielectric constant greater than 5 has a conductive sleeve surrounding a proximal part of the core and a longitudinal feeder structure extending through the core to a connection with the helical antenna elements at a distal end of the core. The antenna is operated in an upper frequency band in which it exhibits a first mode of resonance characterized by current maxima at the connections of the helical elements to the feeder structure and at their junctions with the rim of the sleeve, and in a lower frequency band in which the antenna exhibits a second mode of resonance characterized by current minima in the region of the junctions of the helical elements and the sleeve rim. To permit dual mode operation, the antenna system includes an impedance-matching diplexer having filters coupled between a common port for the antenna and further ports for connection to radio signal processing equipment such as a GPS receiver and a mobile telephone operating in the two frequency bands. In the preferred embodiment, the filters and impedance matching elements are formed as microstrip elements on a single substrate.

100. 发明专利

GB9524754D0 Mobile position determination 未知
公开(公告)号：GB9524754D0
公开(公告)日：1996-04-24
申请号：GB9524754
申请日：1995-12-04
申请人： SYMMETRICOM INC
IPC分类号： G01S1/00 , G01S5/00 , G01S19/04 , H04W64/00
摘要： A position determining system takes the form of a cellular radio system including at least one base station having a base station satellite receiver (6) and a mobile unit including a cellular mobile station (50) coupled to a local satellite receiver (58). The base station transmits base station satellite data via a cellular radio link to the mobile unit, the data including data representing a carrier phase measurement derived from a satellite signal (70) received by the base station satellite receiver (6). The mobile unit determines its position relative to the base station using local satellite data received by the local satellite receiver (58) and corrects errors in this position determination using base station satellite data. The relative positions of the base stations are determined automatically with reference to an external positional reference which may be a satellite-based position determining system.

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