Motorola Corporation

Wei L Tan

Pha C Nguyen

Brian K Terry

Angel Bolanos

A collector-injector mixer circuit (100) has a first differential pair of transistors having first and second transistors (102, 104) whose emitters are connected to a common first emitter terminal (110), and a second differential pair of transistors having third and fourth transistors (106, 108) whose emitters are connected to a common second emitter terminal (112). The bases of the first and fourth transistors (102, 108) are coupled to a common first base terminal (114) and the bases of the second and third transistors (104, 106) are coupled to a common second base terminal (116) between which a mixing signal is applied. A third differential pair of transistors have fifth and sixth transistors (124, 126) wherein collector (130, 132) of the fifth transistor (124) and sixth transistor (126) receive an input signal, an emitter of the fifth and sixth transistors (124, 126) are coupled through resistors (146, 148) to ground, and bases of the fifth and sixth transistors are coupled to a reference current circuit (150).

Collector-injection mixer with radio frequency signal applied to

An antenna system (308, 309, 310, 312, 314, 316, and 317) for a wrist carried selective call receiver (300) comprises at least first (312 and 314) and second (310) elements, coupled to each other and coupled to the selective call receiver to form a first single magnetic loop antenna (312, 308, 316, and 310) having a first physical orientation. At least one of the first and second elements comprises at least one second single magnetic loop antenna (312, 308, 316, 310, 317, 309, and 314) also coupled to the selective call receiver. The second single magnetic loop antenna has a second physical orientation different from the first physical orientation.

Antenna system for a wrist carried selective call receiver

A wrist band loop antenna for a device having a receiver which is intended to be worn on a wearer's wrist comprises a pair of wrist band loop segments which are coupled to the receiver for forming first and second electrical portions of the wrist band loop antenna. A conductive clasp couples to the first and second wrist band loop segments to provide adjustment of the length of the wrist band and provides electrical coupling between first and second wrist band loop segments to form the wrist band loop antenna. An insulator is provided to insulate the conductive clasp from the wearer's wrist which is coupled to the lower surface of the clasp.

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Lake Worth, FL, United States of America

Wei L Tan