Circular-geometry oscillators

5.3GHz 0.18μm CMOS circular-geometry oscillator exploits high Q of slab inductors. The oscillator draws 10mA from 1.4V with a phase noise of -147.3dBc/Hz at 10MHz offset. A second 5.4GHz circular-geometry VCO has a tuning range of 8% with phase noise of -142.2dBc/Hz at 10MHz offset while drawing 12mA from a 1.8V supply

Capacity limits and matching properties of lateral flux integrated capacitors

Theoretical limits for the capacitance density of lateral flux and quasi-fractal capacitors are calculated. These limits are used to investigate the efficiency of various capacitive structures such as lateral flux and quasi-fractal structures. This study leads to two new capacitor structures with high lateral field efficiency. Simulation and experimental results demonstrate higher capacity and superior matching properties compared to the standard horizontal parallel plate and previously reported lateral-field capacitors

Analysis of Internally Bandlimited Multistage Cubic-Term Generators for RF Receivers

Adaptive feedforward error cancellation applied to correct distortion arising from third-order nonlinearities in RF receivers requires low-noise low-power reference cubic nonidealities. Multistage cubic-term generators utilizing cascaded nonlinear operations are ideal in this regard, but the frequency response of the interstage circuitry can introduce errors into the cubing operation. In this paper, an overview of the use of cubic-term generators in receivers relative to other applications is presented. An interstage frequency response plan is presented for a receiver cubic-term generator and is shown to function for arbitrary three-signal third-order intermodulation generation. The noise of such circuits is also considered and is shown to depend on the total incoming signal power across a particular frequency band. Finally, the effects of the interstage group delay are quantified in the context of a relevant communication standard requirement

Phase noise in distributed oscillators

The phase noise of a distributed oscillator is evaluated very simply by identifying an effective capacitance equal to the total capacitance distributed along the transmission lines. The contributions of the various passive and active noise sources to the total phase noise are calculated revealing several guidelines for improved distributed oscillator designs

Equalization of Third-Order Intermodulation Products in Wideband Direct Conversion Receivers

This paper reports a SAW-less direct-conversion receiver which utilizes a mixed-signal feedforward path to regenerate and adaptively cancel IM3 products, thus accomplishing system-level linearization. The receiver system performance is dominated by a custom integrated RF front end implemented in 130-nm CMOS and achieves an uncorrected out-of-band IIP3 of -7.1 dBm under the worst-case UMTS FDD Region 1 blocking specifications. Under IM3 equalization, the receiver achieves an effective IIP3 of +5.3 dBm and meets the UMTS BER sensitivity requirement with 3.7 dB of margin

A fully-integrated 1.8-V, 2.8-W, 1.9-GHz, CMOS power amplifier

This paper demonstrated the first 2-stage, 2.8W, 1.8V, 1.9GHz fully-integrated DAT power amplifier with 50Ω input and output matching using 0.18μm CMOS transistors. It has a small-signal gain of 27dB. The amplifier provides 2.8W of power into a 50Ω load with a PAE of 50%

Phased Array Systems in Silicon

Phased array systems, a special case of MIMO systems, take advantage of spatial directivity and array gain to increase spectral efficiency. Implementing a phased array system at high frequency in a commercial silicon process technology presents several challenges. This article focuses on the architectural and circuit-level trade-offs involved in the design of the first silicon-based fully integrated phased array system operating at 24 GHz. The details of some of the important circuit building blocks are also discussed. The measured results demonstrate the feasibility of using integrated phased arrays for wireless communication and vehicular radar applications at 24 GHz

Extremely wideband signal shaping using one- and two-dimensional nonuniform nonlinear transmission lines

We propose a class of electrical circuits for extremely wideband (EWB) signal shaping. A one-dimensional, nonlinear, nonuniform transmission line is proposed for narrow pulse generation. A two-dimensional transmission lattice is proposed for EWB signal combining. Model equations for the circuits are derived. Theoretical and numerical solutions of the model equations are presented, showing that the circuits can be used for the desired application. The procedure by which the circuits are designed exemplifies a modern, mathematical design methodology for EWB circuits