Technische Universiteit Delft

Seyed Morteza Alavi

Leonardus Cornelis Nicolaas De Vreede

Yiyu Shen

Freerk Van Rijs

Mohsen Hashemi

Robert Jan Bootsman

Leonardus Cornelius Nicolaas De Vreede

Mohammad Reza Beikmirza

Mohammedreza Mehrpoo

Dieuwert Peter Nicolaas Mul

Mohammed Reza Mehrpoo

Rob Heeres

Mikhail Evgenyevich Polushkin

An RF transmitter () having a gate-segmented power output stage () and a digital driver (). The gate-segmented power output stage () includes a field-effect transistor with a plurality of gate fingers () and drain fingers () that define a gate periphery. The field-effect transistor comprises a plurality of power output stage segments () that each correspond to a respective part of the gate periphery, and that each have a respective power output stage segment input (). The digital driver () has control outputs () which are connected to corresponding ones of the respective power output stage segment inputs (), and is configured for individually switching each of the power output stage segments () between an on mode and a cut-off mode in dependence of one or more input signals to obtain a modulated RF carrier signal at an output () of the gate-segmented power output stage ().

Digital transmitter with high power output

An RF transmitter having one or more common-gate, CG, or common-base, CB, configured output stages, and a digitally controlled current source having a plurality of unit cells connected to the output stages, each of the plurality of unit cells comprising a current source. The digitally controlled current source is configured for driving the output stages with respective driving currents originating from the associated current source in each of the plurality of unit cells, in dependence of one or more input signals. The digitally controlled current source further comprises a current diversion path in each of the plurality of unit cells for providing a diversion current to a voltage source having a voltage lower than drain/collector terminals of transistors provided in the CG/CB configured output stages.

Digital transmitter with high linearity for wideband signals

A wideband, linear, direct-digital RF modulator (DDRM) for a digitally-intensive transmitter (DTX) includes an interpolation filter and an in-phase/quadrature (I/Q)-interleaving RF digital-to-analog converter (RF-DAC). The interpolation filter suppresses sampling replicas in the DDRM's output RF spectrum. I/Q interleaving performed by the interleaving RF-DAC avoids problems associated with using two separate I- and Q-path RF-DACs. Each unit cell of the interleaving RF-DAC is capable of producing four unique non-overlapping waveforms covering all four quadrants of the I/Q signal plane. In one embodiment of the invention, the interleaving RF-DAC includes three parallel-connected RF-DACs operating in accordance with a multi-phase set of LO clocks to both cancel 3-order and 5-order LO harmonics generated by the RF-DAC unit cells' interleaving logic and prevent 3-order intermodulation from occurring in the DTX's final stage RF power amplifier.

Digitally-intensive transmitter having wideband, linear, direct-digital RF modulator

A wideband, frequency agile, radio frequency digital-to-analog converter (RF-DAC) based phase modulator includes first, second, and third RF-DACs, each configured to upconvert an input I/Q digital baseband signal pair to a local oscillator (LO) frequency but with the first RF-DAC being driven by a first set of LO clocks, the second RF-DAC being driven by a second set of LO clocks that is forty-five degrees out of phase with respect to the first set of LO clocks, and the third RF-DAC being driven by a third set of LO clocks that is a further forty-five degrees out of phase with respect to the second set of LO clocks. First, second, and third upconverted analog signals produced by the first, second, and third RF-DACs are combined to reinforce the fundamental LO component while canceling 3-order and 5-order LO harmonics.

RF-DAC based phase modulator

Growing community of inventors

Delft, Netherlands

Seyed Morteza Alavi