Cavendish Kinetics’s Tunable RF Circuits

CK’s tunable RF circuits deliver the following benefits to designers of mobile wireless devices:

• High Quality (Q) factor. The Quality (Q) factor is a parameter that describes how energy-transparent a device is. A high Q factor means the device does not subtract as much energy from the circuit. In RF applications, this means lower insertion loss. CK devices have the highest useable Q factor in the industry. MEMS have inherently high Q, and CK takes full advantage of this attribute through careful device and process design of its third-generation MEMS devices, resulting in the smallest MEMS capacitors in the industry – and high Q for the user.

• Low C_min. Parasitic capacitance normally limits design options for RF circuits. Switches and passives have to deal with parasitics on the board as well as capacitance inherent in the passive components. CK devices are carefully designed to minimize the effects of parasitics, allowing lower C values to be used in the circuits. Higher frequency bands require a very low capacitance to maintain efficient operation, and the CK devices offer the lowest C_min values of any tunable capacitor technology.

• Wide tuning range. The tuning range is defined as C_max - C_min. Normally tuning ratios of 5:1 are needed to effectively implement a tunable RF circuit. Other technologies, such as BST, are limited to 3:1 tuning, which greatly limits the range of applications. CK’s third-generation MEMS technology features reliable tuning ranges up to 5:1 with extremely linear code-to-Cvalue performance. Variations are typically less than 0.25LSB.

• Precise C values. Many tuning applications – especially Impedance matching and tunable filters – require precise Cvalues that do not vary over temperature, or device-to-device. CK’s third-generation MEMS technology provides precision to less than 1% variation over the entire temperature operating range, with typical device-to-device variations of <5%.