Abstract: A compact RF differential circuit has a first differential I/O port comprising a first pair of signal carrying terminals which is connected to a source termination and a second differential I/O port comprising a second pair of signal carrying terminals which is connected to a load termination. The common mode impedance measured at either the first or second differential I/O port is zero. The differential mode impedance measured at the first differential I/O port is equal to the differential mode impedance of the source termination, and the differential mode impedance measured at the second differential I/O port of the circuit is equal to the differential mode impedance of the load termination.

Abstract: An RF electronic component for mounting on a substrate includes a housing; and at least one electronic device having an input and/or output incorporated in the housing. At least one input/output terminal connects to a connection pad on the substrate; and an electrical transition provides an electrical connection between the input/output terminal and an input/output of an electronic device incorporated in the electronic component. The electrical transition comprises a side termination at least partially located on an outer surface of the housing; and an array of conductive through holes formed inside the housing at an offset from the side termination. The array is arranged so that the axes of the through holes are substantially mutually parallel and coplanar, and the array of through holes is connected to form a ground plane at the offset from the side termination.

Abstract: A method is disclosed for providing an indication that a vehicle has exceeded a safe driving speed. The speed and position of an obstacle are combined with a driver reaction time to arrive at a safe maximum speed. The driver reaction time is predicted based not only on generic values as in known systems, but also on at least one scaling factor which can be, for example, a scaling factor which penalises increased driving duration, or driver age, or experience, or weather conditions.

Abstract: A switching circuit for use at the antenna of a multiband mobile cellular handset comprises an antenna port 10, a TX low band port 14, a TX high band port 12 and at least one RX port 16. A single pole, triple throw solid state voltage-controlled switch made up of four PIN diodes D1 to D4 selectively connects any one of the TX low band port, TX high band port and RX port to the antenna port. No diplexer is used to separate the low and high band parts o the circuit.

Abstract: A substrate for mounting a device is disclosed. The substrate includes at least one transition for providing an RF connection to a lead of the device, the lead extending from a device input to an otherwise free end. The transition comprises two spaced apart electrically coupled members, the first member occupying at least the same area on a top surface of the substrate as the device lead to which it is to connect, and the second member lying in register with the first member. The transition comprises an input, which is located at the end of the second member which is nearest the free end of the device lead and an output which is located at the opposite end of the first member and which is in register with the device input. The electrical characteristics of the transition are such that the electrical length from the input of the transition to the output of the transition is approximately equal to one half of a wavelength over a given operating frequency band of the device.

Abstract: An SPNT switch has at least two operating states and comprises N circuit branches. Each circuit branch comprises a first input/output port connected to a second input/output port via a series active device, and a phase shifting component connected in series with a shunt active device. When the shunt active device is in an on state, the reflection co-efficient due to a path to ground from the series active device via the phase shifting component and the shunt active device is +1. At least one DC terminal controls the state of the active devices, whereby in one of the operating states of the switch, both active devices are in the on state simultaneously, and in another of the operating states, both active devices are in an off state simultaneously.

Abstract: A substrate for mounting a device is disclosed. The substrate includes at least one transition for providing an RF connection to a lead of the device, the lead extending from a device input to an otherwise free end. The transition comprises two spaced apart electrically coupled members, the first member occupying at least the same area on a top surface of the substrate as the device lead to which it is to connect, and the second member lying in register with the first member. The transition comprises an input, which is located at the end of the second member which is nearest the free end of the device lead and an output which is located at the opposite end of the first member and which is in register with the device input. The electrical characteristics of the transition are such that the electrical length from the input of the transition to the output of the transition is approximately equal to one half of a wavelength over a given operating frequency band of the device.

Abstract: A dual mode antenna switch module (ASM) comprises a UMTS TX port; a UMTS RX port; and a UMTS duplexer, comprising a common port, a TX port coupled to the UMTS TX port and an RX port coupled to the UMTS RX port. The ASM further comprises an antenna port; at least one GSM TX port; and at least one GSM RX port. A multi-port switch has respective ports coupled to the antenna port, the at least one GSM TX port, the at least one GSM RX port, and the common port of said UMTS duplexer. The common port of said duplexer has a reflection co-efficient at said connected multi-port switch port with a magnitude in the range 0.8 to 1.0 and with a phase, ?210° ?+n×360 ?150° where n is an integer.

Abstract: This invention relates to a switching circuit for use at the antenna of a multi-band cellular handset to select between the TX and RX modes of the bands. A number of high isolation switching circuits for selectively connecting a common antenna port to a TX port 2 or an RX port 3 of a multi-band cellular handset are described.

Abstract: An antenna duplexer (14?) comprises a transmission (TX) filter (16) having an input and an output. The TX filter input is arranged to connect to a TX port of a mobile telecommunications handset and the TX filter output is arranged to connect to an antenna (12) for the mobile telecommunications handset. The duplexer further includes a Dual Mode Surface Acoustic Wave (SAW) type receiver (RX) filter (18?) having an input and a balanced output. The RX filter input is arranged to connect to the antenna (12) and the RX filter output is arranged to connect directly to a balanced input RX port of the mobile telecommunications handset.

Abstract: This invention relates to a switching circuit for use at the antenna of a multi-band cellular handset to select between the TX and RX modes of the bands. A number of high isolation switching circuits for selectively connecting a common antenna port to a TX port 2 or an RX port 3 of a multi-band cellular handset are described.

Abstract: A switching circuit for use at the antenna of a multiband mobile cellular handset comprises an antenna port 10, a TX low band port 14, a TX high band port 12 and at least one RX port 16. A single pole, triple throw solid state voltage-controlled switch made up of four PIN diodes D1 to D4 selectively connects any one of the TX low band port, TX high band port and RX port to the antenna port. No diplexer is used to separate the low and high band parts o the circuit.

Abstract: An antenna duplexer (14′) comprises a transmission (TX) filter (16) having an input and an output. The TX filter input is arranged to connect to a TX port of a mobile telecommunications handset and the TX filter output is arranged to connect to an antenna (12) for the mobile telecommunications handset. The duplexer further includes a Dual Mode Surface Acoustic Wave (SAW) type receiver (RX) filter (18′) having an input and a balanced output. The RX filter input is arranged to connect to the antenna (12) and the RX filter output is arranged to connect directly to a balanced input RX port of the mobile telecommunications handset.