Hammad M. Cheema

The last barrier: on-chip antennas

This paper has presented a comprehensive overview of on-chip antennas, which remain the last bottleneck for achieving true SoC RF solutions. CMOS remains the mainstream IC technology choice but is not well suited for on-chip antennas, requiring the use of innovative design techniques to overcome its shortcomings. Codesign of circuits and antennas provide leverage to the designer to achieve optimum performance. The layout of on-chip antennas is dictated by foundry specific rules whereas characterization of on-chip antennas requires special text fixtures. For future highly integrated SoC solutions, foundries will have to provide special layers for efficient on-chip antenna implementations, as they currently do for on-chip inductors. In many of the emerging applications such as THz communication, implantable systems and energy harvesting, on-chip antennas have shown immense potential and are likely to play a major role in shaping up future communication systems.

A 3 mW 54.6 GHz Divide-by-3 Injection Locked Frequency Divider With Resistive Harmonic Enhancement

A 54.6 GHz divide-by-3 injection locked frequency divider with low power consumption is presented. A resistive feedback is implemented to achieve a stable dc input and higher injection efficiency. Compared with the conventional design, it exhibits a better supply voltage rejection and wider locking range while a small silicon area is maintained. Fabricated in a TSMC 65 nm bulk CMOS process, this divider operates from 48.8 to 54.6 GHz and consumes 3 mW from a 0.9 V supply.

3.56-bits/cm Compact Inkjet Printed and Application Specific Chipless RFID Tag

In this letter, a 28.5-bit chipless RFID tag, based on paper substrate and realized using inkjet printing technique is presented. Operating within ultrawideband, the tag occupies a compact size of 2 ×4 cm2. Focusing on applications requiring time and date identification, a novel encoding technique is presented that allows efficient frequency band allocation based on the number of required instances of time and date variables. A figure of merit (FOM) relating coding capacity and tag dimensions coined as code density is also introduced. A systematic design process followed by simulations and verified through measurements reveal a high code density of 3.56 bits/cm2 for the presented chipless tag.

A Compact Kapton-Based Inkjet-Printed Multiband Antenna for Flexible Wireless Devices

A low-cost inkjet-printed multiband antenna envisioned for integration into flexible and conformal mobile devices is presented. The antenna structure contains a novel triangular iterative design with coplanar waveguide (CPW) feed, printed on a Kapton polyimide-based flexible substrate with dimensions of 70×70×0.11 mm3. The antenna covers four wide frequency bands with measured impedance bandwidths of 54.4%, 14%, 23.5% and 17.2%, centered at 1.2, 2.0, 2.6 and 3.4 GHz, respectively, thus, enabling it to cover GSM 900, GPS, UMTS, WLAN, ISM, Bluetooth, LTE 2300/2500 and WiMAX standards. The antenna has omnidirectional radiation pattern with a maximum gain of 2.1 dBi. To characterize the flexibility of the antenna, the fabricated prototype is tested in convex and concave bent configurations for radii of 78 mm and 59 mm. The overall performance remains unaffected, except a minor shift of 20 MHz and 60 MHz in S11, for concave bending at both radii. The compact, lightweight and conformal design as well as multiband performance in bent configurations, proves the suitability of the antenna for future electronic devices.

A Ka Band, Static, MCML Frequency Divider, in Standard 90nm-CMOS LP for 60 GHz Applications

This paper presents a broadband, static, 2:1 frequency divider in a bulk 90 nm CMOS LP (low-power) technology with maximum operating frequency of 35.5 GHz. The divider exhibits an enhanced input sensitivity, below 0 dBm, over a broad input range of 31 GHz and consumes 24 mA from a 1.2 V supply. The phase noise of the divider is -124.6 dBc/Hz at 1 MHz offset from the carrier.

Disposable, Paper-Based, Inkjet-Printed Humidity and H2S Gas Sensor for Passive Sensing Applications

An inkjet-printed, fully passive sensor capable of either humidity or gas sensing is presented herein. The sensor is composed of an interdigitated electrode, a customized printable gas sensitive ink and a specialized dipole antenna for wireless sensing. The interdigitated electrode printed on a paper substrate provides the base conductivity that varies during the sensing process. Aided by the porous nature of the substrate, a change in relative humidity from 18% to 88% decreases the electrode resistance from a few Mega-ohms to the kilo-ohm range. For gas sensing, an additional copper acetate-based customized ink is printed on top of the electrode, which, upon reaction with hydrogen sulphide gas (H2S) changes, both the optical and the electrical properties of the electrode. A fast response time of 3 min is achieved at room temperature for a H2S concentration of 10 ppm at a relative humidity (RH) of 45%. The passive wireless sensing is enabled through an antenna in which the inner loop takes care of conductivity changes in the 4–5 GHz band, whereas the outer-dipole arm is used for chipless identification in the 2–3 GHz band.

A 30 to 44 GHz divide-by-2, quadrature, direct injection locked frequency divider for sliding-IF 60 GHz transceivers

This paper presents a wideband 40 GHz divide-by-2 quadrature injection locked frequency divider (Q-ILFD) as an enabling component for sliding-IF 60 GHz transceivers. The design incorporates direct injection topology and input power matching using interconnect inductances to enhance injection efficiency. This results in an excellent input sensitivity and a wide locking range. Fabricated in a 65nm bulk CMOS technology, the divider operates from 30.3 to 44 GHz (37% locking range) while consuming 9mW from a 1.2V supply. The measured phase noise is −131 dBc/Hz at 1-MHz offset whereas the phase error between I-Q outputs is less than 1.44°.

Monolithic Transformers for High Frequency Bulk CMOS Circuits

3B Abstract — This paper presents two monolithic transformer structures exhibiting high self resonance frequencies(fSR). Effect of positive and negative coupling factor on self resonance frequency is investigated. The transformer turn ratio and structure is selected to improve design and ease layout of a high frequency LNA and VCO. Measurement results of a transformer show good agreement with simulated values and demonstrate a coupling factor of 0.7 at 20 GHz. 4B Index Terms — CMOS integrated circuits, Coupling factor, Monolithic transformer, self resonance frequency.

High capacity polarization sensitive chipless RFID tag

A radio frequency identification (RFID) chipless tag that achieves a high code capacity through multiple closed loop printed resonators is presented. By making the resonators polarization dependent, the same frequency band within UWB from 3.1 to 7.6 GHz is re-used, hence doubling the code capacity of the tag. The chipless tag is excited using linearly polarized vertical and horizontal plane waves and the radar cross section versus frequency is analyzed. Using frequency shift encoding enables each of the six resonators to represent more than one bit. Thus, in a small tag dimension of 6 × 3 cm2, encoding of 28.4 bits is demonstrated.

60-GHz CMOS phase-locked loops

This chapter lays the foundation for the work presented in latter chapters. The potential of 60 GHz frequency bands for high data rate wireless transfer is discussed and promising applications are enlisted. Furthermore, the challenges related to 60 GHz IC design are presented and the chapter concludes with an outline of the book.