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This paper discussed the impact of frequency compensation on the linearity of 2 nd and 3 rd order negative feedback amplifiers from a synthesis point of view. For each compensation method, simple expressions are derived that relate the amount of bandwidth required to get a desired linearity performance up to the end of the information band. The phantom zero technique is concluded to be by far the best compensation method what linearity is concerned.

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Abstract-FM radio receivers require an IF filter for channel selection, customarily set at an IF center frequency of 10.7 MHz. Up until now, the limitations of integrated radio selectivity filters in terms of power dissipation, dynamic range, and cost are such that it is still required to use an external ceramic 10.7-MHz bandpass filter. This paper demonstrates a CMOS switched-capacitor IF filter that can be integrated with most of the rest of the FM receiver, eliminating external components and printed circuit board area. This is made possible through a combination of two techniques: orthogonal hardware modulation, and delta-charge redistribution. It exhibits a tightly controlled center frequency with a of 55 and also contains a programmable gain. The filter occupies an area of 0.7 mm 2 in a 0.6-m CMOS process with poly-poly capacitors. The new filter requires only 16 mW of power, and this is offset by elimination of the power needed in current designs to drive off-chip filters.

This paper presents four compact lumped-element Wilkinson power combiners (WPC) operating at 5 GHz in 28-nm bulk CMOS. To minimize the chip area, the inductances in the designs are implemented using mutually coupled coils. Two designs use star inverting coupled coils (SICC), while the other two employ delta noninverting coupled coils (DNICC). One of the two SICC-based designs (and similarly for the DNICC-based designs) incorporates a second harmonic (2f 0 ) trap to lower the total harmonic distortion and reduce the required inductances by 25%, further reducing the circuits footprint. A design methodology for effectively exploiting the mutual coupling and nullifying the coupling parasitics is presented. The coupling parasitic in the DNICC-based design is exploited to provide the WPC isolation resistance, resulting in a lumped-element WPC requiring only three components: a coupled coil and two capacitors. The measurement and simulation results are presented to confirm the theory validity. The SICC-based WPC with an area of 0.13 mm 2 achieved input return losses (RL) >17.5 dB, output RL > 11.8 dB, isolation >11.2 dB, and insertion losses (IL) <1.5 dB across 3.5-5.4-GHz frequency range. Its variant with a 2f 0 trap achieved, from 3.5-5.35 GHz, input RL >18.2 dB, output RL >11.6 dB, isolation >11 dB, IL <1.4 dB, and peak 2f 0 rejection of 18 dB at 10.2 GHz in an area of 0.13 mm 2 .The DNICC-based WPC with an area of 0.11 mm 2 achieved input RL and isolation >10 dB, output RL >15.3 dB, and IL <1.2 dB across 4.1-5.45-GHz frequency range. Its variant with a 2f 0 trap achieved, from 4.3-5.3 GHz, input RL and isolation >10.1 dB, output RL >14.6, IL <1.2 dB, and peak 2f 0 rejection of 23 dB at 10.4 GHz in an area of 0.09 mm 2 .

An analog filter is designed based upon the requirement of an interference rejection filter for the Quadrature Downconversion Autocorrelation Receiver (QDAR). The transfer function of an eight-order elliptic bandpass filter is selected. As a result, a state-space approach (i.e. the orthonormal form [1]) is adopted, which is intrinsically semi-optimized for dynamic range, has low sensitivity, high sparsity and its coefficients can be physically implemented. Each coefficient in the state-space description of the filter is implemented at circuit level using a novel 2-stage gm cell based upon the principle of negative feedback. Simulation results in IBM's Bi-CMOS 0.18 µm technology show that the interference rejection filter requires a total current of 90 mA at a 1.8 V power supply. The 1-dB compression point of the filter is at 565 mV and the SNR is 47.5 dB. On performing a Monte Carlo simulation, it becomes evident that the overall filters transfer response does not suffer from process variations.