S 波段 GaAs 超低噪声限幅低噪声放大器芯片的研制
Development of an S-band GaAs Ultra Low NoiseLimiter Low-noise Amplifier Chip
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摘要: 本文将限幅器嵌入到了低噪声放大器的输入级匹配电路,使得整体限幅放大电路的噪声系数为低噪声放大器的最小噪声系数而不需再加上限幅器的损耗,从而有效降低了整体限幅低噪声放大器的噪声系数。 在此基础上,设计并实现了一款 S 波段限幅低噪声放大器芯片,实现了超低噪声与高耐功率的性能。 测试结果表明,该款芯片在目前相近频段所有限幅低噪声放大器产品中噪声系数最小。 在2. 7 GHz~ 3. 5 GHz 工作频带内,实测噪声系数 NF≤0. 85 dB,增益≥29 dB,带内增益平坦度≤±0. 3 dB,静态工作电流≤25 mA,1 dB 压缩点输出功率≥8 dBm。 在耐功率50 W(250 μs 脉宽、25%占空比)下试验 30 min 后不烧毁,恢复到常温时,噪声几乎无变化。 芯片尺寸为 3 450 μm×1 600 μm×100 μm。Abstract: A design method which takes the limiter as part of the input matching network of the low noise amplifier is proposed in this paper. The noise figure of the whole circuit can be decreased into the minimum noise figure of the low noise amplifier, instead of adding the limiter′s loss to the noise figure of low noise amplifier, which can dramatically decrease the noise figure of the whole circuit. Based on this, an S-band limiter low-noise amplifier chip is designed and implemented, which attains the properties of ultra low noise figure and high power endurance simultaneously. The test results show that this limiter low noise amplifier chip has the lowest noise figure among all the current products working at the similar frequency band. Within the bandwidth of 2. 7 GHz~ 3. 5 GHz. The noise figure is below 0. 85 dB, the gain is above 29 dB with flatness below ±0. 3 dB, the quiescent current is below 25 mA and the output power at 1 dB is above 8 dBm. The limiter low noise amplifier can endure 50 W input pulse power ( pulse width 250 μs, duty cycle 25%) for 30 minutes. When it recovers to room temperature, the noise figure is barely changed. The size of the chip is 3 450 μm×1 600 μm×100 μm.