SOI CMOS tunable capacitors for RF antenna aperture tuning

During the last decade, Ultra-WideBand applications showed many interests for radio and imaging applications in the [3.1-4.9 GHz] frequency band. To realize such applications in other frequency domains, the instantaneous frequency of the impulse signal is commonly used. This paper describes the design of an Instantaneous Frequency Measurement system in order to show the feasibility to use it for Ultra-WideBand impulse radio radar and imaging applications. The integrated part of the system is constituted of a full-wave rectifier, a delay cell and an analog multiplier. These devices was designed in CMOS 130 nm technology and the post-layout simulation are shown in comparison to theoretical Matlab simulations.

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“…Here, the definition (2) of the instantaneous frequency is not so far. The result in (11) is divided by the delay 𝜏 and the estimation gives:…”

Section: Theoretical Methods For Instantaneous Frequency Measurementmentioning

confidence: 99%

“…Thus in order to be more flexible for testing and to have the possibility to measure pulses with different carrier frequency, a tunable capacitor [11] was built on node A. Thanks to two NMOS RF switches, four values of capacitance will be available.…”

Section: B Delay Cellsmentioning

confidence: 99%

Instantaneous frequency measurement for IR-UWB signal in CMOS 130 nm

Goavec

Vauché

Gaubert

et al. 2016

2016 IEEE International Conference on Electronics, Circuits and Systems (ICECS)

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“…The Tunable Capacitor (TC) used in this study is a Silicon-On-Insulator (SOI) CMOS integrated circuit based on a network of binary-weighted switched capacitors [7].…”

Section: Tunable Capacitor Designmentioning

confidence: 99%

Large-Signal Analysis and Characterization of a RF SOI-based Tunable Notch Antenna for LTE in TV White Space Frequency Spectrum

Abdallah¹,

Bories²,

Nicolas³

et al. 2017

EAI Endorsed Transactions on Cognitive Communications

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The demand for spectrum resources has increased dramatically with the explosion of wireless mobile devices and services. The Cognitive Radio (CR) associated with TV white space frequencies defined between 470 MHz to 790 MHz is one solution to excel the spectrum resources shortage and address LTE low bands. The antenna design to cover such a wide band is a twofold challenge. First Electromagnetic fundamental limits impose a tradeoff between antenna efficiency, miniaturization and its frequency band wideness, secondly to be implemented in portable device (around 10 cm typical length) the antenna miniaturization needs is to be strong such as in λ/6 (where λ is the wavelength at 500 MHz). Thus, frequency reconfigurable antennas are suitable candidates and can be easy integrated. In this paper a compact frequencyagile notch antenna for LTE low-band using TV white space frequencies is designed and fabricated. The 18 x 3 mm notch size (area dedicated for the antenna) is only λ/33 at 500 MHz. The antenna aperture tuning is provided by a SOI CMOS tunable capacitor. The novelty of this paper is to present not only classical metrics (gain, return loss…) but also the experimental characterization of parameters that are usually used for active RF components. The non-standard tunable capacitor RF non linearity analysis is carried on and analyzed. The simulated and experimental performances are presented and demonstrate antenna tuning operation from 800 MHz down to 500 MHz. The slot electrical near field distribution is also investigated to confirm acceptable electrical field within the tunable component. High linearity is validated with measured ACLR levels lower than -30 dBc up to 22 dBm input power in the considered frequency range.

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