一种具备自动增益控制功能的宽带正交解调器

发布时间：2018-05-20 17:44

本文选题：正交解调器 + 无线接收机　；参考：《西安交通大学学报》2017年12期

【摘要】：为了实现无线电接收机对多个通信标准的兼容和对信号链路增益的自动调节,提出了一种适用于宽带(0.8~2.7GHz)接收机并具备自动增益控制(AGC)功能的正交解调器。该解调器的信号主路上采用一个宽带设计的射频可变增益放大器和一个中频可变增益放大器,频率变换则通过一个增益可调的吉尔伯特单元实现。在信号反馈环路上采用一个均方根功率检波器检测输出信号的幅度并转换成直流电压,然后通过检波器输出的直流电压控制主路上各个模块的增益,从而形成一个AGC闭环系统。该解调器仅采用模拟电路实现AGC功能,避免了传统数字辅助型AGC需要大量端口、算法实现复杂和精度受有限步长的限制等缺点。该解调器在0.18μm BiCMOS工艺平台下设计并流片验证,测试结果表明:在0.8~2.7GHz内,正交解调器的可调转换增益范围为-36~36dB,解调带宽为100MHz;最大增益下噪声系数为9dB,正交相位误差1.6°,幅度误差为0.9dB。
[Abstract]:In order to realize the compatibility of radio receiver with multiple communication standards and the automatic adjustment of signal link gain, a quadrature demodulator with automatic gain control (AGC) function is proposed, which is suitable for wideband (0.8 ~ 2.7GHz) receiver and has the function of automatic gain control (AGC). The demodulator uses a wideband designed RF variable gain amplifier and an intermediate frequency variable gain amplifier. The frequency conversion is realized by a gain adjustable Gilbert cell. In the signal feedback loop, a root mean square power detector is used to detect the amplitude of the output signal and convert it to DC voltage. Then the output DC voltage of the detector controls the gain of each module in the main circuit, thus forming a AGC closed loop system. The demodulator only uses analog circuit to realize AGC function, which avoids the disadvantages of traditional digitally aided AGC which requires a large number of ports. The algorithm is complex and the precision is limited by finite step size. The demodulator is designed and verified on a 0.18 渭 m BiCMOS technology platform. The test results show that the tunable conversion gain range of the quadrature demodulator is -36 ~ 36 dB, the demodulation bandwidth is 100 MHz in 0.8~2.7GHz, the noise coefficient is 9 dB, the orthogonal phase error is 1.6 掳, and the amplitude error is 0.9 dB under the maximum gain.
【作者单位】：中国科学院上海微系统与信息技术研究所;中国科学院大学微电子学院;
【基金】：国家自然科学基金资助项目(61404151,61574153)
【分类号】：TN763

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