Dawid W. Rosolowski

A S-band 7 W GaN HEMT adaptive power amplifier

In the paper a 7 W GaN HEMT adaptive power amplifier (APA) operating over 1.8 to 4.0 GHz is presented. To control APA states the six pin diodes as regulators have been used in both input and output matching networks. The design is based on the small-signal approach for modelling active elements such as transistor and regulators. The measured results of APA have proven usefulness of the proposed design methodology. The APA is controlled by specialized unit - Universal Controller of Adaptation.

An ultrawideband 1 to 6 GHz 0-IF radio receiver with 500 MHz of instantaneous bandwidth

This paper is related to the project of an ultrawideband radio receiver operating between 1 and 6 GHz with instantaneous bandwidth of 500 MHz. A single frequency conversion (0-IF) architecture is based on analog I/Q demodulator (ADL5380) and two channel 14-bit analog-to-digital converter (AD9680). Preliminary measurements of the receiver have been performed and presented in the paper. Key results include: noise figure NF < 7.5 dB, dynamic range over 62 dB (enhanced by frontend and baseband leveling circuitry), high linearity: IIP3 > 21 dBm.

Low phase noise synthesizer optimized for wideband 0-IF radio receiver

In this paper the performance of two wideband PLL frequency synthesizers realized with ADF5355 and HMC833 chips respectively has been compared. Both of them were investigated as a local oscillator for 0IF receiver operating from 1 GHz to 6 GHz. In order to provide required harmonics level below -40 dBc the final solution is based on the ADF5355 followed by a switched bank of four low pass filters. The phase noise level is better than -90 dBc @ 1 kHz and spurious are lower than -70 dBc.

Transverters for TDD and FDD ISM 2.4GHZ Radio Systems

The paper describes development of a technique and equipment to convert signals from TDD or FDD radio systems operating over popular ISM 2.4 GHz-band up to the less crowded, licensed 3.5GHz or 4.4GHz bands. The technique of bands conversion consists in a connection to the existing infrastructures RF up/down converter modules (transverter) with T/R switches or duplexer for TDD or FDD systems, respectively. Currently, the 3.5GHz FDD transverters cooperate in 17 locations with the IRT2000 digital radio access system used by El-net NETIA group and 4.4GHz TDD transverters work together with 802.11b WLAN AP utilized by Military Communication Institute.

A 10W GaN based X-band T/R module for AESA

The paper presents the results of a project leading to design and fabrication of a transmitting-receiving module destined for application in an active electronically scanned array (AESA). The module is supposed to operate in the band from 9 GHz to 10 GHz. GaAs technology core chip is applied and it is used to drive power amplifiers based on GaN technology. The shape of the module enclosure follows the requirements of limited space available in an X-band AESA.

A 250 W RF Pulse Power Source for linear accelerator

In this paper a 250W solid state RF Pulse Power Source (PPS) operating over a 2995MHz to 3001MHz frequency range with only 100Hz frequency step and from 5.6μs to 8.4μs pulse width at the duty cycle below 0.5% is presented. The device was optimized to deliver the synchronized high-frequency-stability RF pulse for Linear Accelerator processing. The pulse power level can be controlled within 18dB dynamic range with power drop during the pulse less than 0.3dB. The phase noise level and long-term stability including VCO pulling effect of the synthesized RF signal is below -85dBc/Hz@1kHz and less than 0.2ppm, respectively. The advanced reconfiguration, diagnostic and protection features built into the RF pulse source are remotely controlled via Ethernet.