Anyone who has been online in a moving vehicle knows how frustrating it can be to lose the signal in a pinch. Users need high-speed connections and bandwidth to be able to view and send messages, play music and video, or hold multi-party video conferences very smoothly, regardless of traffic mode.
Phasor is a developer of high-throughput, modular, digital phased array antennas and a market leader in mobile broadband, providing highly stable, reliable satellite connectivity in aerospace, marine, land mobile and defense applications. The company’s electronically steered antennas are based on the latest developments in dynamic beamforming technology and system architecture. Phasor’s broadband and satellite solutions for mobile applications allow high-speed two-way broadband Internet connections using electronically controlled phased array antennas.
The Phasor antenna consists of multiple small repeating modules mounted on two PCBs, the upper PCB being the patch antenna array on the front and the Phasor Application Specific Integrated Circuit (ASIC) on the back. The lower backplane provides power, control, and communications for the system.
The latest antenna technology developed by Phasor eliminates the need for satellite dishes, enabling the application of thin, flat, solid-state fixed antenna systems embedded on top of vehicles. The thin unit is less than 25mm thick and performs as well as a 2.4m or wider dish. The two main properties of this antenna are integrability and expandability: the integrability allows the antenna to fit into most vehicle form factors; the scalability of the entire modular architecture helps the antenna meet any future needs.
When Phasor wanted to develop a unique mobile communication system, it realized that its products needed to not only combine high power density with thin components, but also deliver extremely high currents at very low voltages.
The solution that meets all of these requirements is Vicor’s Factorized Power Architecture™ (FPA™), and the two companies have worked closely together for the past four years to ensure products are developed that meet Phasor’s system requirements and fully meet customer needs. Phasor found that Vicor FPA systems lead the market in size and density, as well as delivering modular and scalable high performance.
Today, as the load voltage of advanced processors drops below 1 volt, these processors require more current. Point-of-load density and low noise are increasingly important to processor performance. An ongoing challenge for system designers is how to accommodate lower voltages with faster transient response and higher power system efficiency in shrinking circuit boards.
A factorial power architecture solves these problems—it takes the regulation and conversion functions of a DC-DC converter and breaks it down into two components. This allows for full optimization of functions: a high-efficiency voltage regulator and a high-density current transmitter for a variety of low-voltage, high-current loads. The FPA consists of a Voltage Regulator Module (PRM™) and a Current Multiplier (VTM™). These two devices work together, each device can effectively play its special role, and finally complete the DC-DC conversion function.
The PRM can provide a regulated output voltage or “factored bus” from an unregulated input supply. This busbar supplies power to one or more VTMs and not only brings the factored busbar voltage to the level required by its load, but also provides isolation. Therefore, the PRM-VTM chipset provides full regulated isolated DC-DC converter functionality.
A factorial power supply means more space at the point of load, power consumption is halved, and voltage regulation can be located remotely.
The Components Behind Factorized Power Supplies: PRM and VTM
Both PRM and VTM are components that implement FPA. The PRM regulator uses a patented zero-voltage switching (ZVS) buck-boost regulator control architecture for efficient buck-boost regulation and soft-start. The highest efficiency is achieved when VIN = VOUT; the latest PRM achieves a peak efficiency of 99.3%.
The VTM current multiplier is a high-efficiency transformer module using a proprietary Zero Current Switching/Zero Voltage Switching (ZCS/ZVS) Sine Amplitude Converter (SAC™). Its operation is based on pure sinusoidal waveforms with high spectral purity and common-mode symmetry. These characteristics mean that not only does it not produce the harmonic content typical of PWM-type conversions, it also produces very low noise. The control architecture locks the operating frequency to the power stage resonant frequency and not only supports efficiencies up to 97%, but also minimizes output impedance by effectively eliminating reactive components. This extremely low inductive-free output impedance enables almost instantaneous response to step changes in load current.
The VTM can respond to load changes with an effective switching frequency of 3.5MHz, whether the amplitude is less than 1 microsecond. The high bandwidth of the VTM eliminates the need for large point-of-load capacitors. Even without any external output capacitors, the VTM’s output has very limited voltage perturbation in response to sudden power surges. Very few external bypass capacitors (in the form of low ESR/ESL ceramic capacitors) are sufficient to eliminate any transient voltage overshoot.
An important factor in the successful operation of Phasor’s antennas is the Vicor system’s ability to convert 48V power to 1.5V (and even lower for newer antennas). The main challenge in the design of the Phasor ASIC power system is the need to achieve this transformation at 65A (or even 80A).
Phasor has considered other solutions, but there are several shortcomings. First, some alternatives do not address issues such as heat dissipation. With a height of 25mm, there is simply no room for a cooling fan, so Phasor needed a solution that not only conducts heat dissipation, but also generates (and wastes) as little heat as possible. Second, traditional transformation methods may involve multiple hard-switching converters with multiple different phases to achieve 65A current, which may generate a large amount of electromagnetic interference. The VTM is a resonant converter and therefore has extremely low noise compared to hard-switched converters. At the same time, Vicor solutions outperform traditional DC/DC converters in terms of power supply and efficiency.
In addition, the FPA solutions provided by Vicor have been well-proven by several large processor companies over the past 10 years.
The work done by Vicor and Phasor is a major breakthrough that promises to be a multi-million dollar market. The development of this market will have two important elements: the transition from existing geostationary satellite networks to other forms of broadband; and the release of thousands of low-Earth orbit satellite systems that will provide long-range connectivity at broadband speeds.
For both companies, the next challenge is to develop technologies that deliver higher currents at lower voltages (1V).
With Vicor and Phasor’s long-term symbiotic strategic relationship, not only will the antenna specialists keep the modular power specialists up to date on the power requirements of the latest ASICs, but Vicor will also keep Phasor up to date with factored power supplies. The growing collaboration between the two companies continues.
The Links: CM300DY-24A LM64K101