A 8–18 GHz Low Noise Variable Gain Amplifier with 30 dB Gain Control Range

This brief presents a single-stage current steering, low noise variable gain amplifier with a novel amplitude and phase error reduction method. The design is implemented in IHP's 0.13 μm SiGe BiCMOS technology for 8–18 GHz. At the highest gain setting, S21 is 12.4 dB, the minimum noise figure is 1.93 dB, and the maximum input 1-dB compression point is 3.9 dBm. Fine gain control steps are achieved up to 30 dB with 0.5 dB increments. The maximum measured rms phase and amplitude errors are 12.3° and 0.49 dB, respectively. The proposed design consumes 24 mW DC power and occupies 0.58 mm² including pads. To the best of the authors' knowledge, our work achieves the lowest noise figure and highest IP 1dB are achieved among the published variable gain amplifiers.