Abstract: Double-sideband suppressed carrier (DSSC) modulation is used in concert with local oscillator (LO) rejection to create a steep notch for a communication signal within a jamming signal. The double-sideband suppressed carrier modulation may use upper and lower sidebands which are symmetrical or asymmetrical. An equivalent very high Q band-pass notch is synthesized within the jamming sideband signals. The jammer signal can be split into four signals in quadrature phases and fed to a four-square vertical dipole antenna design that results in a null along the axis of the array's center on which a communication antenna is aligned.

Abstract: In an IC packaging scheme, a multilayer substrate is composed of electrically conductive layers of interconnects, separated by insulative layers of epoxy resin or ceramic and connected by vias. Passive elements are integrated within the substrate at the definition stage during layout of the interconnects. The passives can be used to enhance the electrical performance of the active circuit die to a maximum extent allowed by the material technology used for the substrate. Material selection for the package is made to allow for the best passive integration for a given circuit design. Typical applications include power supply bypass capacitors, radio frequency tuning, and impedance matching. The incorporation of passives in the packaging substrate creates a new class of electrically tailorable packaging that can derive improved performance for any given die design over existing approaches.

Abstract: An antenna array for direction-agile applications, such as r.f. packet mesh networks, employs a plurality of quarter-wave radiators disposed normally to a ground plane on a dielectric backing and switching elements for selecting a desired receiving direction and transmission direction and minimizing interference from signals in opposing directions. A control system selects and switches direction rapidly enough to receive and transmit digipeating signals in selected different directions using the phasing and switching elements. A specific embodiment employs eight radiators of 0.2625 electrical wavelengths (quarter wave plus 5%) disposed equidistant along a circle within a circular ground plane in a pattern which is 1/4 wavelength from the outer boundary of the ground plane, each radiator being disposed at least 0.15 wavelengths to about 0.25 wavelengths from adjacent radiators in a circular pattern. The antenna is characterized by eight electronically switchable radiating directions (at 45.degree.