Vishay Intertechnology, Inc.

Rf Waves Ltd.

David Ben-Bassat

Dani Alon

Moshe Lerner

Reuven Katraro

Eli Bershadsky

Marina Kravchik

A novel digitally controlled antenna tuning circuit that enables the implementation of low cost, wideband tuning circuits for antennas in receive applications. The invention is operative to switch a plurality of tuning elements into and out of a main receive signal path. Each individual tuning element is switched into or out of the receive signal path using a single PIN diode. For series connected tuning elements, the diode is connected in parallel to the tuning element. For tuning elements connected in parallel, the diode is connected in series with the tuning element. The diodes are switched in accordance with control voltages which forward bias the diodes to effectively create a low resistance path thus either inserting or removing a tuning element from the receive signal path depending on its configuration in the circuit.

Digitally controlled antenna tuning circuit for radio frequency receivers

A novel antenna system for receiving transmissions in the VHF and UHF frequency bands particularly suitable as a miniaturized antenna for UHF reception, such as of digital video broadcasting transmissions. The antenna system utilizes a combination of three techniques including (1) the use of dialect loading using a high dielectric constant ceramic substrate; (2) an antenna dielectrically loaded and tuned to a significantly higher frequency than desired; and (3) use of a tuning circuit to compensate for the frequency offset of the antenna thereby shifting the resonant frequency to cover the entire band. The antenna is intentionally designed to be too small to radiate at the frequency of interest. The antenna element is then 'forced' to be tuned to the desired lower frequency using passive (or active) reactive components as part of a tuning circuit. Multi-band operation is achieved by providing a bypass switch to connect the antenna element either to (1) a first receiver without the tuning circuit (i.e. high frequency tuning) or (2) a second receiver with the tuning circuit (i.e. low frequency tuning).

Miniature sub-resonant multi-band VHF-UHF antenna

A dielectric ceramic composition has a dielectric constant, K, of at least 200 and a dielectric loss, DF, of 0.0006 or less at 1 MHz. The dielectric ceramic composition may be formed by sintering by firing in air without a controlled atmosphere. The dielectric ceramic composition may have a major component of 92.49 to 97.5 wt. % containing 60.15 to 68.2 wt. % strontium titanate, 11.02 to 23.59 wt. % calcium titanate and 7.11 to 21.32 wt. % barium titanate; and a minor component of 2.50 to 7.51 wt. % containing 1.18 to 3.55 wt. % calcium zirconate, 0.50 to 1.54 wt. % bismuth trioxide, 0.2 to 0.59 wt. % zirconia, 0.02 to 0.07 wt. % manganese dioxide, 0.12 to 0.35 wt. % zinc oxide, 0.12 to 0.35 wt. % lead-free glass frit, 0.24 to 0.71 wt. % kaolin clay and 0.12 to 0.35 wt. % cerium oxide. UHF antennas and monolithic ceramic components may use the dielectric ceramic composition.

Ceramic dielectric formulation for broad band UHF antenna

A bidirectional direct sequence spread spectrum half-duplex RF modem. that can be applied to transmit and receive numerous types of analog and digital pulse modulation. The modem incorporates a SAW based correlator for performing the spreading and de-spreading functions in the transmitter and receiver. A programmable frequency synthesizer provides the frequency source for various signals in the modem including the local oscillator (LO), IF interrogating pulse and clock signals. An upconverter/downconverter provides frequency translation to the desired frequency band. Pulse gating and interrogating pulse shaping are employed to reduce the spectral side bands of the transmitted spread pulse. The RF modem operates as an analog or digital pulse transmitter and receiver. It is adapted to be generic and is versatile enough to be used in many different types of data communication systems, such as OOK, PWM and PPM. The RF modem can be used as the physical (PHY) layer in a layered communication system such as the ISO OSI communication stack. In an alternative embodiment, the transmission bit rate is increased by using a plurality of correlators wherein each is configured with a unique function (i.e., code) that is orthogonal to the other functions.

RF modem utilizing saw device with pulse shaping and programmable frequency synthesizer

A bidirectional direct sequence spread spectrum half-duplex RF modem that can be applied to transmit and receive numerous types of analog and digital pulse modulation. The modem incorporates a SAW based correlator for performing the spreading and de-spreading functions in the transmitter and receiver. A SAW resonator fabricated on the same monolithic substrate provides the frequency source for the oscillator. An upconverter/downconverter provides frequency translation to the desired frequency band. Pulse gating and interrogating pulse shaping are employed to reduce the spectral side bands of the transmitted spread pulse. The RF modem operates as an analog or digital pulse transmitter and receiver. It is adapted to be generic and is versatile enough to be used in many different types of data communication systems, such as OOK, PWM and PPM. The RF modem can be used as the physical (PHY) layer in a layered communication system such as the ISO OSI communication stack. In an alternative embodiment, the transmission bit rate is increased by using a plurality of correlators wherein each is configured with a unique function (i.e., code) that is orthogonal with all other functions.

RF modem and communications transceiver utilizing saw device and pulse shaping

A bidirectional direct sequence spread spectrum half-duplex RF modem which can be applied to transmit and receive numerous types of analog and digital pulse modulation. The modem incorporates two different SAW devices fabricated on a single monolithic substrate. A first SAW device is used as a resonator in the oscillator circuit while a second SAW device is used as the correlator for transmit and receive operations. The RF modem operates as an analog or digital pulse transmitter and receiver and is adapted to be generic and versatile enough to be used in many different types of data communication systems, such as OOK, PWM and PPM. The RF modem can be used as the physical (PHY) layer in a layered communication system such as the ISO OSI communication stack. In an alternative embodiment, the transmission bit rate is increased using a plurality of correlators wherein each is configured with a unique function (i.e., code) that is orthogonal with all other functions.

Growing community of inventors

Yehud, Israel

David Ben-Bassat