Title :
A 45 dB variable gain low noise MMIC amplifier
Author :
Masud, M. Anowar ; Zirath, Herbert ; Kelly, Matthew
Author_Institution :
Microwave Electron. Lab., Chalmers Univ. of Technol., Gothenburg, Sweden
Abstract :
A variable gain amplifier operating at 2.5 GHz based on single ended topology has been designed and characterized. Three such stages were cascaded preceded by a single stage LNA. A source follower is used at the output as an active load matching. Overall dynamic gain variation is 45 dB with a maximum gain of 47 dB. The -3 dB bandwidth is 0.800 GHz. A minimum noise figure of 0.81 dB is obtained in the highest gain mode. Maximum value of 1 dB compression at the output is -7.2 dBm and the corresponding third order intercept point is +5.3 dBm. Consumed DC power 285 mW and is immune to gain variation. The circuit is implemented with GaAs pHEMT technology. The combined area occupied by the multistage low noise VGA and the single ended VGA is 3.5 mm × 3 mm.
Keywords :
III-V semiconductors; MMIC amplifiers; amplification; gallium arsenide; interference suppression; low noise amplifiers; network topology; power HEMT; 0.8 GHz; 0.81 dB; 10.5 mm; 2.5 GHz; 285 mW; 3 mm; 3.5 mm; 45 dB; GaAs; GaAs pHEMT; active load matching; single ended VGA; single ended topology; source follower; variable gain low noise MMIC amplifier; CMOS technology; Circuits; Communication system control; Feeds; Frequency; Gain; HEMTs; Low-noise amplifiers; MMICs; Topology;
Conference_Titel :
Microwave Conference, 2005 European
Print_ISBN :
2-9600551-2-8
DOI :
10.1109/EUMC.2005.1610264
