This Small Business Innovation Research Program (SBIR) Phase I project proposes to develop a new class of integrated voltage tunable RF inductors and transformers, which are based on the voltage control of magnetism in ferroelectric/magnetic composite materials. These integrated voltage tunable RF inductors and transformers are compact and power efficient, having a wide inductance tuning range, a significantly boosted operating frequency range at several GHz and enhanced quality factor over conventional integrated magnetic inductors. When combined with different commercially available varactor technologies, these tunable inductors and transformers will considerably extend the tunable frequency range of critical RF reconfigurable components and circuits such as tunable impedance matching networks, tunable filters, tunable power amplifiers, tunable low-noise amplifiers, and tunable phase shifters. Such tunable inductors and transformers will lead to transformative ultra-wideband reconfigurable communication systems that are of critical importance in today's highly crowded and complex electromagnetic environment.
The broader impact/commercial potential of this project includes the development a new class of compact and power efficient voltage tunable inductors and transformers, which will enable novel adaptive RF components such as tunable impedance matching networks, tunable filters, tunable power amplifiers, tunable low-noise amplifiers with significantly enhanced tuning frequency ranges, and also create totally new markets for tunable RF components. Compared to integrated RF magnetic inductors which typically show low quality factors at GHz, the voltage tunable inductors and transformers will have significantly enhanced quality factor and extended operating frequency in addition to being efficiently tunable across a wide inductance range. These tunable RF inductors and transformers can nicely complement other commercially available varactor technologies and provide a significantly enhanced tuning frequency range for circuits such as tunable impedance matching networks, antenna tuners, tunable power amplifiers and tunable low noise amplifiers, which will enable new markets for reconfigurable RF components, circuits and communication systems, and have great impacts on different industries such as smart phones, laptops, tablets, E-readers, etc.
This Small Business Innovation Research Program (SBIR) Phase I project proposes to develop a new class of integrated voltage tunable RF inductors and transformers, which are based on the voltage control of magnetism in ferroelectric/magnetic composite materials. During this project period, we demonstrated new integrated GHz magnetic inductors based on solenoid structures with FeGaB/Al2O3 multilayer films, which show significantly enhanced inductance and quality factor at GHz frequencies over their air core counterparts. These inductors show excellent high-frequency performance with a wide operation frequency range of DC ~ 2.5GHz, in which the inductance of the integrated magnetic inductors show >100% enhancement compared with that of the same size air core inductor. Voltage tunable magnetoelectric inductors were fabricated with MEMS processing by putting these inductors on ferroelectric slab, which showed a voltage tunable inductance of >100% between 0.5~3.5 GHz. These novel voltage tunable GHz inductors with giant tunable inductance show great promise for applications in radio frequency integrated circuits. At the same time, we have demonstrated integrated RF magnetic transformers which show enhanced inductance and quality factor at GHz compared to their non-magnetic counterpart. This project led to two journal papers and two conferences presentations, and one patent that is applied in the U.S. and in China. The above demonstration in Phase I period provides a solid foundation for our Phase II project to bring these voltage tunable RF inductors and transformers both in discrete form and on RFIC to the market. This project will enable novel adaptive RF components such as tunable impedance matching networks, tunable filters, tunable power amplifiers, tunable low-noise amplifiers with significantly enhanced tuning frequency ranges, and also create totally new markets for tunable RF components. Compared to integrated RF magnetic inductors which typically show low quality factors at GHz, the voltage tunable inductors and transformers will have significantly enhanced quality factor and extended operating frequency in addition to being efficiently tunable across a wide inductance range. These tunable RF inductors and transformers can nicely complement other commercially available varactor technologies and provide a significantly enhanced tuning frequency range for circuits such as tunable impedance matching networks, antenna tuners, tunable power amplifiers and tunable low noise amplifiers. These new voltage-tunable RF inductors and transformer are expected to significantly boost semiconductor and defense industry applications. The new compact and power efficient voltage tunable inductors make up the missing link in achieving significantly enhanced RF tunable frequency range in a tuned circuit, also called an L-C tank circuit. State-of-the-art RF circuits in smart phones and other mobile devices rely on the tunable capacitance of RF varactors (semiconductor diodes that act as a voltage-dependent capacitor) in RF L-C tank circuits, leading to limited tunable frequency range. The new compact and power-efficient voltage-tunable RF inductors add another dimension and are developed by magnetic/piezoelectric thin film deposition with MEMS processing, resulting in large voltage-tunable inductance advancements of greater than 100 percent for tunable RF circuit designs. These voltage-tunable RF inductors constitute a new RF tuning technology that will lead to significantly enhanced tuning range and reduced RF circuit modules. We expect the new inductors to bring about revolutionary changes in tunable RF circuit designs, which will result in higher quality smart phones with lower costs and more compact size. At the same time, this novel advancement enables new flexibility and capability in the design of RF circuits, and ultimately will lead to reduced cost and higher performance in mobile RF products.
