Abstract: Systems, devices, and methods for providing deployable and collapsible Quadrifilar Helical Antennas (QHA) on small satellites to improve communications in low earth orbit satellites. Monopole antennas are very popular for use on small satellites, generally because they are relatively easy to attach. By using circularly polarized antennas for the spacecraft and the ground station, polarization losses are virtually eliminated. The QHA can be designed to have a wide range of circularly polarized antenna patterns. Low power transmitters are employed on the small satellite to be consistent with the available energy. The communication link budgets are dependent on good radiation pattern characteristics for the small satellite downlink where higher data rates are required. Quadrifilar Helical Antennas can be collapsed and stowed inside a module to mount inside typical cubes known as 1U through 27U size small satellites. After launch from the rocket, the QHA can be deployed to its stored memory shape.

Abstract: A communications apparatus. The apparatus comprises a transmitting antenna, a receiving antenna, a first serial configuration of a first power amplifier and a first matching network for producing a first signal, the first power amplifier operating in a first frequency band, a second serial configuration of a second power amplifier and a second matching network for producing a second signal, the second power amplifier operating in a second frequency band, a first switching element for switchably supplying the first signal or the second signal to the transmitting antenna, a first and a second receiver; and a second switching element for switchably directing a signal received at the receiving antenna to the first receiver or the second receiver.

Abstract: A modular communications apparatus. The apparatus comprises a dielectric substrate, a radiating structure disposed on a surface of the substrate, and an electronics module disposed within the dielectric substrate. The electronics module comprises a power amplifier and signal receiving components. The apparatus further comprises fixed length transmission lines connecting the radiating structure and the electronics module, a length of each transmission line selected to present a desired impedance at an input and an output terminal of each transmission line without requiring separate impedance matching elements.

Abstract: A communications apparatus comprising a first antenna, a first serial configuration of a first power amplifier and a first matching network, a second serial configuration of a second power amplifier and a second matching network, a switching element for switchably selecting the first or the second serial configuration for supplying a signal to the first antenna, the first and the second power amplifiers supplying a respective first signal of a first power and a second signal of a second power different than the first power to the first antenna for transmitting and the first and the second matching networks presenting respective first and second impedances to the respective first and second power amplifiers, the first and the second impedances responsive respectively to a power-related parameter of the first and the second signals.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: An antenna for a communications device having configurable elements controlled to modify an antenna impedance and/or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

Abstract: An antenna for a communications device having configurable elements controlled to modify an antenna impedance and/or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: An antenna operative in a plurality of frequency bands. The antenna comprises first and second high band resonators, a resonating meanderline and a counterpoise. A ground return conductively couples one or more regions of the counterpoise to the meanderline. One or more of the first resonating element, the second resonating element and the resonating meanderline are coupled by magnetic and/or capacitive coupling to provide operation in the plurality of frequency bands.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A disk-like impedance matching element disposed at a lower end of the antenna matches a source impedance to an antenna impedance. In certain embodiments a first crossbar connector on a substrate disposed at an upper end of the antenna electrically connects two helical filars to form a first filar pair and a second crossbar connector disposed on the substrate connects two filars to form a second filar pair.

Abstract: An antenna for a communications device having configurable elements controlled to modify an antenna impedance and/or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

Abstract: An antenna for a communications device having configurable elements controlled to modify an antenna impedance and/or an antenna resonant frequency to improve performance of the communications device. The antenna impedance is controlled to substantially match to an output impedance of a power amplifier that supplies the antenna with a signal for transmission. The antenna resonant frequency is controlled to overcome the effects of various operating conditions that can detune the antenna or in response to an operable frequency band.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A disk-like impedance matching element disposed at a lower end of the antenna matches a source impedance to an antenna impedance. In certain embodiments a first crossbar connector on a substrate disposed at an upper end of the antenna electrically connects two helical filars to form a first filar pair and a second crossbar connector disposed on the substrate connects two filars to form a second filar pair.

Abstract: An antenna operative in a plurality of frequency bands. The antenna comprises first and second high band resonators, a resonating meanderline and a counterpoise. A ground return conductively couples one or more regions of the counterpoise to the meanderline. One or more of the first resonating element, the second resonating element and the resonating meanderline are coupled by magnetic and/or capacitive coupling to provide operation in the plurality of frequency bands.

Abstract: A shield for shielding radio frequency emissions being emitted from a communications antenna. The shield has a first layer of material having the physical property of generally absorbing radio frequency electromagnetic emissions and a second layer of material having the physical property of generally reflecting radio frequency emissions. The first layer of material is positioned between the second layer of material and the communications antenna. Therefore, the first layer of material absorbs a portion of the radio frequency emissions from the communications antenna, and the second layer of material reflects back the remaining emissions to the first layer of material. Therefore, the first layer absorbs a further portion of the remaining emissions. A layer of absorbing material is placed between the combined first & second layers and a material that is transparent to radio frequency emissions and through which the communications antenna radiates radio frequency energy.

Abstract: A shield for shielding radio frequency emissions being emitted from a communications antenna. The shield has a first layer of material having the physical property of generally absorbing radio frequency electromagnetic emissions and a second layer of material having the physical property of generally reflecting radio frequency emissions. The first layer of material is positioned between the second layer of material and the communications antenna. Therefore, the first layer of material absorbs a portion of the radio frequency emissions from the communications antenna, and the second layer of material reflects back the remaining emissions to the first layer of material. Therefore, the first layer absorbs a further portion of the remaining emissions. A layer of absorbing material is placed between the combined first & second layers and a material that is transparent to radio frequency emissions and through which the communications antenna radiates radio frequency energy.