Gec-marconi Limited

Marconi Electronic Systems Limited

Brian Jeffrey Buck

Liam Michael Devlin

An integrated transceiver circuit packaged component including a transceiver circuit having a bandstop filter (29) provided therein for filtering both the received and transmitted signals to remove unwanted components therefrom.

Integrated transceiver circuit packaged component

A switching arrangement for establishing a signal path between any one of a plurality of first ports and a common port and for varying the attenuation of at least one of the ports comprises in the signal path of each attenuatable port a first switching element and attenuating circuitry connectable by further switching circuitry across the first switching element, the first switching element constituting the sole series element in that path. The attenuating circuitry comprises a resistive network and the further switching circuitry comprises second switching elements connected to respective ends of the first switching element and to respective points of the resistive network for introducing one of a number of resistive states into the signal path. The relevant port is isolated either by switching the first and second switching elements OFF, or by switching OFF the first element and also a third switching element connected in series between a second switching element and that end of the first switching element which lies downstream in the signal flow path. The switching elements may be FETs and the switching arrangement may take the form of a single-pole, double-throw (SPDT) switch or a switch of any number of 'poles' or 'throws'.

Switching arrangement with combined attenuation and selection stage

An electrical apparatus has a number of units (1 to 6), each of which is capable of presenting a transfer function of a different value to an input signal. It also includes control circuitry (7, 9) whereby a desired selection of units (1 to 6) can be made so as to present to the input signal a total value of desired transfer function. The values of the units are chosen such that the ratio (B) between a function value and the next smaller value is less than 2:1.

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Northampton, United Kingdom

Brian Jeffrey Buck