Abstract: A wide band dual mode antenna (10) includes an electrically conductive monopole portion (12), an electrically insulating core (32) having a dielectric constant and adjacent to the monopole portion (12), and an electrically conductive wire (50) adjacent to the core (32) and having a total length associated with a first resonant frequency. The wire (50) has first and second ends (52, 54), wherein the first end (52) is electrically coupled to the monopole portion (12) and the second end (54) is electrically floating. The wire (50) includes a plurality of intercoupled segments (56, 58, 62) that are adapted to create a current null point between the first and second ends (52, 54) at a second resonant frequency to define first and second portions of the wire (50).

Abstract: The present disclosure is related to an antenna (129) adapted to receive signals in multiple frequency bands, and comprises a fixed whip antenna (406) and a helical coil antenna (408) coupled to a single feedpoint. The antenna may also include a monopole common to the fixed whip antenna and the helical coil antenna. A single matching circuit (130) is adapted to provide matching for both the whip antenna and the helical coil antenna. According to one embodiment, the antenna can also be reduced in size by attaching a disc (704) to the end of the whip portion of the antenna, while decreasing the pitch of the helical coil. Finally, a clip (210) can be used below a threaded nut of a housing to provide a feed point for the antenna to further reduce the electrical lengths of the fixed whip antenna and a helical coil antenna.

Abstract: A filter duplexer, such as a filter duplexer for a radio transceiver, of minimum dimensions is disclosed. First and second filter portions of the duplexer each include a plurality of transmission lines. Cross sections of the plurality of transmission lines of each filter portion are of at least two different geometries. The amount of coupling between adjacent ones of the resonators, as well as the loading capacitances of such resonators, is controlled by the relative geometric configuration of the adjacent ones of the resonators. Because the amount of coupling between the resonators and the loading capacitances of the resonators is determinative of the filter characteristics of the filter duplexer, desired filter characteristics may be effectuated by careful selection of the geometric configurations of the resonators of each filter portion.

Abstract: A filter assembly comprised of a dielectric filter and a shield positioned about the dielectric filter. The dielectric filter may be surface-mounted upon a circuit board and includes at least one notch formed to extend along a side face surface thereof. The shield is integrally formed of two sheets of an electromagnetic wave-absorptive material interconnected by a shoulder forming a right angle to fit about two sides of the dielectric filter. At least one projecting prong, corresponding in number and position with the at least one notch of the dielectric filter, extends beyond an end surface of one of the sheets of the shield to interfittingly engage with a corresponding notch formed on the filter. The shield is positioned about the dielectric filter prior to tuning of the filter, and openings are formed to extend through the shield to permit access to the dielectric filter to permit tuning thereof once the shield is positioned thereabout.

Abstract: A dielectric filter construction having at least two resonating cavities extending longitudinally through a block of dielectric material. At least one of the resonating cavities is of a cross-sectional area which is elongated in a transverse direction, and at least one notch is formed to extend longitudinally along at least one of the surfaces of the block of dielectric material between adjacent ones of the resonating cavities. By appropriate selection of the amount of elongation of the cross-section of the resonating cavity, and the location and dimension of the notch formed along the surface of the block, the component values of the component elements comprising the filter may be selected over an increased range without altering the physical size of the filter.

Abstract: Disclosed is an apparatus for pressure sensor compensation. The invention is best suited for pressure sensors of the type which may be mounted about a flexible member such that the resistance of one or more strain gauge resistors mounted thereon changes as pressure is exerted upon the flexible member. The pressure sensing apparatus comprises a bridge resistor arrangement for sensing pressure, and bridge control circuitry, coupled to an input terminal of the bridge, for compensating temperature induced variances in the bridge by controlling the voltage at the input terminal. The bridge has at least a first strain gauge resistor mounted on the flexible member, and at least one output terminal having a voltage which changes as pressure is exerted upon the flexible member. The bridge control circuitry has an additional strain gauge resistor which is used to monitor the temperature of the first strain gauge resistor.

Abstract: A competitive game is disclosed in which the competitors spray each other with water, and which is therefore well suited for outdoor recreational activity in hot weather. The players operate switches to attack each other by means of spray nozzles, and also to defend themselves against such attacks. The defender, if his or her reaction to a warning light is quick enough, can abort the attack entirely. He or she can also divert it to another player. The game accommodates four players who can team up in various combinations to attack and defend in concert, the combinations being determined by a sophisticated Boolean function which is programmed into the game's logic. The game is also playable in a rotated mode which rescrambles the Boolean function to present a different set of strategy considerations.