A direct digital synthesis transmitter that uses a programmable digital circuit to generate a digital signal representing at least one radio frequency signal, the generated signal is filtered, amplified by an amplifier, and provided to a transmission antenna without upconversion. The transmitter generating the digital signal at a desired output frequency range such that a frequency upconverter is not needed to produce signals in the desired radio frequency range.

An IQ generator capable of consuming lower power and occupying smaller die area. The IQ generator is configured without any synthesizer and divide-by-2 circuitry. The IQ generator may be configured to convert one or more phase outputs of a test tone generator (TTG) into I and Q signals. The IQ generator may receive as inputs differential outputs of a single phase of a TTG and/or multiple phase outputs of a TTG. The IQ generator may include one or more delay paths configured to generate the I and Q signals, and a calibration circuitry configured to compare the average pulse widths of the I and Q signals and provide one or more control signals to the one or more delay paths such that the I and Q signals are orthogonal in phase.

An IQ generator capable of consuming lower power and occupying smaller die area. The IQ generator is configured without any synthesizer and divide-by-2 circuitry. The IQ generator may be configured to convert one or more phase outputs of a test tone generator (TTG) into I and Q signals. The IQ generator may receive as inputs differential outputs of a single phase of a TTG and/or multiple phase outputs of a TTG. The IQ generator may include one or more delay paths configured to generate the I and Q signals, and a calibration circuitry configured to compare the average pulse widths of the I and Q signals and provide one or more control signals to the one or more delay paths such that the I and Q signals are orthogonal in phase.

An outdoor satellite receiving unit (ODU) receives several independent satellite signals, selects two signals with a switch matrix, downconverts the two signals to a bandstacked signal with a high and a low band signal, and outputs the bandstacked signal on the same cable to receiver units. Several satellite signals can be selected in groups of two or more and output to independent receiver units. Signal selecting is performed at the received radio frequency (RF) and bandstacking is performed with a single downconversion step to an intermediate frequency (IF). Channel stacking on the same cable of more than two channels from several satellites can be achieved by using frequency agile downconverters and bandpass filters prior to combining at the IF output. A slow transitioning switch minimizes signal disturbances when switching and maintains input impedance at a constant value.

An outdoor satellite receiving unit (ODU) receives several independent satellite signals, selects two signals with a switch matrix, downconverts the two signals to a bandstacked signal with a high and a low band signal, and outputs the bandstacked signal on the same cable to receiver units. Several satellite signals can be selected in groups of two or more and output to independent receiver units. Signal selecting is performed at the received radio frequency (RF) and bandstacking is performed with a single downconversion step to an intermediate frequency (IF). Channel stacking on the same cable of more than two channels from several satellites can be achieved by using frequency agile downconverters and bandpass filters prior to combining at the IF output. A slow transitioning switch minimizes signal disturbances when switching and maintains input impedance at a constant value.

A method and transmission system for amplifying and providing navigation signals. The system comprises a splitter circuit configured to receive a plurality of radio frequency (RF) signals oscillating at at least two different frequencies f.sub.1 and f.sub.2. The splitter circuit is further configured to split and forward the RF signals having the f.sub.1 frequency to a first bandpass filter and the RF signals having the f.sub.2 frequency to a second bandpass filter. The system further comprises a first tunable amplifier configured to receive the RF signals from the first bandpass filter. The system further comprises a second tunable amplifier configured to receive the RF signals from the second bandpass filter at substantially the same time as the first tunable amplifier's receipt of the RF signals from the first bandpass filter. The first tunable amplifier is further configured to amplify its RF signals across a first band centered around the frequency f.sub.1. The second tunable amplifier is further configured to amplify its RF signals across a second band centered around the frequency f.sub.2. The amplified RF signals are fed substantially concurrently into a mixer circuit for transmission via an RF antenna to a navigation receiver.

A method and transmission system for amplifying and providing navigation signals. The system comprises a splitter circuit configured to receive a plurality of radio frequency (RF) signals oscillating at at least two different frequencies f.sub.1 and f.sub.2. The splitter circuit is further configured to split and forward the RF signals having the f.sub.1 frequency to a first bandpass filter and the RF signals having the f.sub.2 frequency to a second bandpass filter. The system further comprises a first tunable amplifier configured to receive the RF signals from the first bandpass filter. The system further comprises a second tunable amplifier configured to receive the RF signals from the second bandpass filter at substantially the same time as the first tunable amplifier's receipt of the RF signals from the first bandpass filter. The first tunable amplifier is further configured to amplify its RF signals across a first band centered around the frequency f.sub.1. The second tunable amplifier is further configured to amplify its RF signals across a second band centered around the frequency f.sub.2. The amplified RF signals are fed substantially concurrently into a mixer circuit for transmission via an RF antenna to a navigation receiver.

An LNB downconverter comprising: two LNBs configured to receive their respective satellite signals: the first and second LNB being configured to output, four IF signals of different polarization and frequency range to a respective first and second Cross-bar Switch (CBS); wherein the first and second CBS, are configured to accept four RF inputs, and routing them, to any of four outputs, as configured by a Controller: wherein outputs of CBSs are connected to respective Satellite Channel Routers (SCRs) configured by the Controller to shift the frequency of their input signals to fixed intermediate frequencies; wherein outputs of SCRs are connected to respective Band Pass Filters (BPFs) whereas the fixed intermediate frequencies of SCRs are different and wherein the band passed by each BPF is non-overlapping; an Adder adding the signals on different frequencies, output by each BPF, to form a single output signal comprising data from both satellite signals.

An LNB downconverter comprising: two LNBs configured to receive their respective satellite signals: the first and second LNB being configured to output, four IF signals of different polarization and frequency range to a respective first and second Cross-bar Switch (CBS); wherein the first and second CBS, are configured to accept four RF inputs, and routing them, to any of four outputs, as configured by a Controller: wherein outputs of CBSs are connected to respective Satellite Channel Routers (SCRs) configured by the Controller to shift the frequency of their input signals to fixed intermediate frequencies; wherein outputs of SCRs are connected to respective Band Pass Filters (BPFs) whereas the fixed intermediate frequencies of SCRs are different and wherein the band passed by each BPF is non-overlapping; an Adder adding the signals on different frequencies, output by each BPF, to form a single output signal comprising data from both satellite signals.

An RF switch circuit and method for switching RF signals that may be fabricated using common integrated circuit materials such as silicon, particularly using insulating substrate technologies. The RF switch includes switching and shunting transistor groupings to alternatively couple RF input signals to a common RF node, each controlled by a switching control voltage (SW) or its inverse (SW_), which are approximately symmetrical about ground. The transistor groupings each comprise one or more insulating gate FET transistors connected together in a “stacked” series channel configuration, which increases the breakdown voltage across the series connected transistors and improves RF switch compression. A fully integrated RF switch is described including control logic and a negative voltage generator with the RF switch elements. In one embodiment, the fully integrated RF switch includes an oscillator, a charge pump, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit.