Abstract: A mobile radio frequency identification (RFID) reader system is provided. The RFID reader system includes an RFID reader. The RFID reader system further includes a primary antenna for transmitting RFID signals to acquire RFID information from RFID item tags and a secondary antenna for transmitting RFID signals to acquire RFID information from one of RFID shelf tags and RFID floor tags.

Abstract: In accordance with principles of the present invention, a two or more pole dielectric resonator circuit is provided with resonators that are elliptical in cross section orthogonal to the longitudinal axis. The resonators are mounted so that they are rotatable about their longitudinal axes, such that the straight line distance between two adjacent resonators measured in a straight line between orthogonal to and intersecting the longitudinal axes of the two resonators is a function of the orientation of the resonators about their longitudinal axes. The resonators can be oriented about their longitudinal axes in any orientation to adjust their spacing, which is directly proportional to their coupling magnitude, which, in turn, is proportional to the bandwidth of the circuit.

Abstract: A dielectric resonator with an air (or other dielectric) gap axially interrupting the body of the resonator and circuits employing such resonators. Preferably, the resonator body is conical or a stepped cylinder. However, the invention also is workable with a straight-sided cylindrical resonator body.

Abstract: In order to permit electronic tuning of the frequency of a circuit including dielectric resonators, such as a dielectric resonator filter, tuning plates are employed adjacent the individual dielectric resonators. The tuning plates comprises two separate conductive portions and an electronically tunable element electrically coupled therebetween. The electronically tunable element can be any electronic component that will permit changing the capacitance between the two separate conductive portions of the tuning plates by altering the current or voltage supplied to the electronically tunable element. Such components include virtually any two or three terminal semiconductor device. However, preferable devices include varactor diodes and PIN diodes.

Abstract: An integrated circuit including a first signal line disposed on a semiconductor substrate, a second signal line disposed on a first dielectric layer, the first dielectric layer disposed on the semiconductor substrate, a third signal line disposed on a second dielectric layer, the second dielectric layer disposed on the first dielectric layer, and at least two vias connecting the first signal line to the second signal line, wherein the second signal line does not span the region directly beneath the third signal line, and wherein at least a portion of the first signal line extends into the region directly beneath the third signal line.

Abstract: An apparatus for propagating high frequency energy hag a wavelength of .lambda. in a dielectric medium has first and second signal lines, substantially coplanar with each other, and carrying high frequency energy, A ground trace separates the signal lines and has a plurality of vias, each spaced a distance greater than one quarter .lambda. and less than one half .lambda. apart from another one of the vias.

Abstract: A packaged integrated circuit configured for interconnection to an external component comprises a die (1) having a high frequency contact (8), the die (1) being disposed on a lead frame (3). The lead frame (3) comprises a plurality of leads (9). At least two of the leads are first and second RF port leads (9a, 9b) which are electrically connected to the RF port. When mounted to a printed circuit board substrate, there is a capacitor (12) connected between the first and second high frequency contact (8) leads (9a, 9b) to achieve frequency specific signal attenuation at an unwanted frequency with minimal contribution of insertion loss at a desired frequency.

Abstract: A control circuit is provided that can be used to compensate for pinch off voltage sensitive circuits. The control circuit comprises a control FET (26) having a gate (27), a drain (29), and a source (28). The control FET source (28) is connected to a tracking potential (23) through control FET source resistor (31) in series with a constant voltage drop element (32). A control voltage input (22) is applied to the control FET drain (29). A current flow through the control FET (26) results in a transfer function that is substantially linear for linear changes in control voltage input below a voltage pinch off value of the control FET (26). As the voltage control output (23) approaches the pinch off voltage value of the control FET (26), smaller changes in control voltage output (23) are realized for the same change in control voltage input (22).