Koninklijke Philips Corporation N.v.

Nxp B.v.

Anthony D Sayers

Paul R Marshall

Eise Carel Dijkmans

Adrian G Spencer

Eric J Van Der Zwan

William B Donaldson

An analogue to digital conversion unit () comprises three analogue to digital converters (ADCs) () having different dynamic ranges. A lowest dynamic range ADC () and middle dynamic range ADC () have saturation detectors SAT for outputting a signal when the amplitude of an input analogue signal reaches their respective dynamic ranges and saturates them. The middle dynamic range ADC () and highest dynamic range ADC have enable inputs EN for switching themselves on. The output of the saturation detector SAT of the lowest dynamic range ADC () is connected to the enable input EN of the middle dynamic range ADC (). The output of the saturation detector SAT of the middle dynamic range ADC () is connected to the enable input EN of the highest dynamic range ADC (). So, whilst the middle and the highest dynamic range ADCs () are normally switched off, when the lowest dynamic range ADC becomes saturated, the middle dynamic range ADC () is switched on; and when the middle dynamic range ADC () is saturated, the highest dynamic range ADC () is switched on. The input analogue signal is therefore converted to a digital output using the ADC () having the lowest sufficient dynamic range and the higher dynamic range ADCs () are switched off unless needed.

Method and apparatus for analogue to digital conversion

A slave radio station establishes communization with a master radio station by transmitting a signal intermittently, listening for a response, and saving power by deactivating its transmitter and receiver at other times. When the master radio station responds, the slave station may synchronize periods of receiver activation with a beacon signal transmitted periodically by the master station and may cease transmission of the intermittent signal.

Method to reduce power consumption in a radio communication system and apparatus therefor

A radio transceiver capable of transmitting and receiving on a common radio channel in a half duplex mode includes a direct conversion transmitter and a low IF receiver. A common signal generator () comprises a first and second frequency generator (). The first frequency generator generates a carrier frequency signal which is used by both the transmitter and receiver. During reception, the second frequency generator generates an offset signal at the low IF frequency which is mixed with the carrier frequency signal to form a down conversion signal. During transmission, modulation is applied either directly to the carrier frequency signal in one embodiment, or to the offset signal which is then mixed with the carrier frequency signal to form a modulated carrier frequency signal in another embodiment.

Direct conversion radio transceiver

A slave radio transceiver for use in a frequency hopping radio system synchronizes by receiving on a sequence of simultaneous combinations of radio channels until a paging message is received from a master transceiver, and may then revert to single channel frequency hopping operation. The slave's multi-channel receiver is sub-equipped to receive simultaneously on a only sub-set (PFPF) of the channels within its bandwidth, the received channels being selected by independent programming within the bandwidth. The channels received simultaneously may be selected to correspond to different degrees of misalignment between the master and slave.

Method and apparatus for synchronizing frequency hopping transceivers

An RF circuit configured to inteface a balanced port ( ) with an unbalanced port ( ) by emulating the function of a balun. Reactive components ( ) in both branches of a balanced circuit form two resonant circuits by resonating with parasitic reactance. At a predetermined operating centre frequency, one of the two resonant circuits is above resonance and the other is below resonance, resulting in a 180&deg; phase difference between the signals delivered by the two branches. When used to interface an unbalanced signal source ( ) to a balanced load ( ), the input impedance may be set to a real value matching the output impedance of the signal source by selection of the reactive component ( ) values.

RF circuit

A receiver with an integrated mixer/Sigma-Delta Modulator configuration for digitizing a relatively low-bandwidth signal modulated on a high-frequency carrier, for example in a radio receiver. The Sigma-Delta Modulator has an continuous-time loop filter (F , F ) with anti-aliasing characteristics which eliminate the need for a separate lowpass filter between the mixer (MX) and the Sigma-Delta Modulator.

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Furnace Geern, United Kingdom

Anthony D Sayers