Cavendish Kinetics was founded in 1994 to develop MEMS devices in standard CMOS processes. The company originally was developing Non Volatile Memory IP (see July 2004 profile), but has refocused on MEMS-based RF tuning solutions for mobile device manufacturers to improve connectivity between wireless devices and cell towers.
The company has secured funding from Tallwood Venture Capital, Wellington Partners, Celtic House Venture Partners, Qualcomm Ventures, Torteval Investments, Clarium Holdings, Inter Ikea Finance, and Sagentia Group. In June 2011, Cavendish closed a $10M financing round, adding Qualcomm to the current investor group. The company is based in Silicon Valley, has 35 employees and has offices in Korea, Taiwan, China and The Netherlands.
Shipped as a chip scale package (CSP), Cavendish’s Digital Variable Capacitor (DVC) technology is used to tune antennas, power amplifiers and filters to significantly improve RF connection quality and signal strength. RF tuning is widely viewed as a leading technology solution for LTE, LTE-A and 4G wireless standards.
The Cavendish device improves the quality of RF signal by using a large array of bi-state MEMS capacitors on a CMOS chip to provide a variable capacitance to the RF circuit. A Cavendish device behaves like a bank of 32 high-precision, high-Q capacitors using a 1P32T switch with zero insertion loss. Cavendish delivers the lowest Cmin in the industry, capable of 0.5pF and below. Cavendish devices, at 2 mm2 and 0.4mm thick, allow for straightforward antenna structure integration.
Cavendish’s tunable RF circuits feature the smallest MEMS capacitors in the industry, according to the company, and high Quality (Q) factor, which translates to low insertion loss. The devices offer the lowest Cmin values of any tunable capacitor technology, minimizing the effects of parasitics. Tuning ratios of 5:1 are typically needed to effectively implement a tunable RF circuit. Other technologies, such as BST, are limited to 3:1 tuning, which limits the range of applications. Cavendish’s third-generation MEMS technology features tuning ranges up to 5:1 with extremely linear code-to-Cvalue performance. The technology also provides precision to less than 1% variation over the entire temperature operating range, with typical device-to-device variations of <5%.
The Cavendish process uses standard CMOS equipment and materials to create highly reliable structures that are built in a commercial CMOS foundry. Cavendish takes advantage of the precision of thin-film deposition, which is key to CMOS circuit performance. The Cavendish devices do not require a package and can be flip-chip mounted directly on antenna structures or inside multi-chip modules, which eliminates performance-destroying parasitics. Cavendish’s technology of sub-encapsulation enables MEMS to be built entirely free of contamination, eliminating the contamination that was the largest source of failure in previous RF MEMS approaches and improving performance.
Development of the Cavendish technology and tuning components has yielded more than 100 patents covering the process technology, the MEMS design and integration with CMOS. More than 40 patents already have been granted.
Antenna Frequency Tuning in mobile devices changes the resonant frequency of the antenna and enables much higher antenna efficiency. RF switches can be used for AFT; however, they can reduce efficiency by up to 50%. Because the Cavendish components have an Equivalent Series Resistance (ESR) comparable to a passive component without needing a lossy RF switch, overall RF system performance is greatly improved. Customers using Cavendish production devices have seen performance improved by 2-3dB in low bands used for LTE/ 4G devices, which results in much higher data rates for 4G users, more efficient network operations for wireless operators and lower BoM costs for device makers.
TowerJazz and Cavendish Kinetics are collaborating to bring MEMS tunable RF solutions to the consumer mobile wireless market. The process combines Cavendish NanoMech MEMS technology with the TowerJazz power CMOS process and custom RF interconnect in a single chip solution. Fabrication includes standard CMOS processing steps, but uses a novel technique that encapsulates the MEMS elements inside tiny micro-cavities to isolate the moving parts from the outside world. The encapsulation is performed within the semiconductor wafer fab process, not at packaging assembly facilities.
The Cavendish NanoMech MEMS technology has passed rigorous reliability testing and enables products boasting advantages in size and performance compared to other technologies. NanoMech MEMS technology can be combined with other TowerJazz technologies such as SOI CMOS, SiGe BiCMOS and TSVs to service a wide variety of emerging applications.
In addition to antenna tuning and impedance matching, other devices and functions within the radio front-end of mobile devices, such as broadband power amps (PAs), can also benefit from Cavendish’s RF tuning devices, as well as phase shifting. High-performance tunable filters are under development in partnership between Cavendish and other industry leaders.
Competitors include Paratek, WiSpry and DelfMEMS, among others. However, Cavendish says the biggest competitor is simply inertia. Designers are not used to having a zero-loss tunable capacitor in their toolkit.
Cavendish is shipping antenna frequency tuning products that widen the number of frequency bands supported by a single antenna to strategic partners for sampling to end customers. The variable capacitor products are ramping production now.
Dennis Yost, President and CEO (previously VP and GM of the CMP business unit at Novellus, COO at Lightpath Technologies, and GM and Managing Director at Applied Materials)
Richard Knipe, Ph.D., VP of Engineering and CTO (22-year career at TI, serving as R&D Manager Digital Micromirror Devices division and Technology Development Manager)
Patrick Murray, CFO (previously CFO of Serious Energy, CFO of WhereNet and Director of Finance for Maxim)
Charles Smith, Ph.D., Founder & Chief Scientific Officer (Professor at Cambridge University UK, where he is a member of the Semiconductor Physics group at the Cavendish Laboratory)
Atul Shingal, EVP of Operations (previously VP of Operations at Inphi, VP of Operations and IT at SiRF, and VP of Operations for Globespan Virata)
Paul Tornatta, VP of Product and Customer Engineering (previously CTO of Skycross, a mobile antenna supplier)
Larry Morrell, EVP, Marketing and Business Development (previously VP and GM of the IP Products Division at Impinj)
Lewis Boore, VP of Sales (previously VP of Marketing & Sales for WiSpry)