A 3^rd/5^th Order Active RC Chebyshev Analog Baseband Low-Pass Filter With Reconfigurable Bandwidth and Gain

Abstract

The design of 3 rd /5 th order active RC Chebyshev low-pass filter (LPF) with reconfigurable bandwidth and gain is based on 55 nm CMOS technology. The filter is integrated into draft IEEE 802.11ax concurrent dual band four antenna transceiver analog baseband circuit. Programmable capacitor bank of the filter is used to adjust bandwidth. The typical bandwidth of receiving filter is 10/20/40 MHz, and that of transmitting filter is 12/24/50 MHz. Adjust the gain ranging from -10 to 18 dB in passband by programmable resistor bank. The current consumption of typical bandwidth of receiving filter is 2.08 mA at a 1.5 V supply and has properties of 10 MHz bandwidth (BW), 36 dB gain, -62 dBm input signal, -39 dB third intermodulation distortion (IMD3), 17.1 nV/√Hz equivalent input noise (EIN). As for transmitting filter, the current consumption of typical bandwidth is 1.25 mA at a 1.5 V supply and has the properties of 10 MHz BW, -6 dB gain, 0 dBm input signal, -38 dB IMD3, 75 nV/√Hz EIN. Area of the whole filter is 0.08 mm 2 . INDEX TERMS Active RC, analog baseband, low-pass filter.

An Analog Baseband Circuit for Wireless Local Area Networks Transceiver in 55 nm CMOS Technology

“…In addition, the area of the LPF-receiver and the area of the LPF-transmitter was 302 µm * 263 µm (about 0.08 mm 2 ) and 181 µm * 263 µm (0.048 mm 2 ), respectively. After multiplexing the LPFtransmitter, the area was reduced by about 37.5% [16]. The total area of the PGA-receiver and the PGA-transmitter was 0.013 mm 2 without multiplexing.…”

“…In this design, the order of the filter is configurable. The LPF-receiver is the 5th order, and the LPF-transmitter is the 3rd order [16]. Typical bandwidth (BW) of the LPF-receiver and the LPF-transmitter are 10/20/40 MHz and 12/24/50 MHz, respectively.…”

“…Gain reconfiguration is changed by adjusting the size of the resistor bank. Resistor bank is applied to both the LPF-receiver and the LPF-transmitter [16]. 1 R to n R are different values corresponding to different gains.…”

“…The high-order filter composed by the method of trapezoidal filter synthesis was less sensitive to component mismatch and is more suitable for high-precision filters. Therefore, in our design, the RLC trapezoidal filter synthesis method was adopted to realize the full differential structure of the 3rd/5th order configurable filter [16].…”

Low-Power Current Integrating Flat-Passband Infinite Impulse Response Filter for Sensor Read-Out Integrated Circuit in 65-nm CMOS Technology

“…The analog filter adopted in existing integrated circuits has limited reconfigurability. That is, to change the filtering characteristics, sizes of passive components such as resistors or capacitors must be varied or the transconductance must be adjusted over a wide range [1][2][3]. On the other hand, current integrating filters have high reconfigurability, making them suitable for integrated circuits because their filtering characteristics can be changed by adjusting the ratio of sampling capacitances or clock frequencies [4][5][6][7].…”