SatNow recently interviewed Alexander (Sasha) Wolloch, Founder and CEO of Raltron. He holds an electrical engineering degree from Ecole Supérieure d'Électricité (1976) and an MBA from the University of Paris (1978). Sasha began his career at ITT as a design engineer, later moving to the U.S. to manage technical marketing for its crystal and oscillator products. He founded Raltron in Miami in 1983 and has since grown it from a small start-up into a global electronic component supplier serving numerous Fortune 100 companies. Most recently, he has driven the company’s expansion in Miami, Fl designed and produced high performance OCXOs for telecommunications, high end instrumentation and LEO satellite applications.
Q. Raltron has been supplying frequency control and RF components for many years. How long have you been supporting the space and satellite industry, and how has your presence in this market evolved over time?
Alexander Wolloch: Raltron has been working in this market for 3 years. Initially we were only working with a few smaller customers, however as our products and knowledge within this market have developed, we are gaining traction with larger LEO constellations.
Q. What products does Raltron currently offer for space and satellite applications, and which product categories are seeing the strongest demand from satellite and spacecraft manufacturers today?
Alexander Wolloch: Raltron is primarily focused on supplying precision OCXOs for the LEO market and are currently being designed into numerous applications. With our new manufacturing facility in Miami, FL, we are looking forward to growing this product portfolio in the future! In addition to the OCXOs, products such as VCXO’s, TCXO’s and Crystal Filters are also being manufactured in our Miami facility.
Q. Why are oscillators such critical components in satellite and space systems? Can you explain the key functions they perform and the applications they support onboard spacecraft?
Alexander Wolloch: Oscillators are critical components for a variety of systems on a satellite. They provide a stable frequency source to generate carrier signals for communication, provide precise clocking to digital systems for timing and synchronization as well as provide a stable frequency for guidance systems.
Q. What differentiates a standard commercial oscillator from one designed or qualified for space applications? What additional design and performance considerations come into play?
Alexander Wolloch: Performance criteria can be like that of commercial oscillators, however the testing, validation and qualification process for oscillators used in space applications is far more stringent than commercial parts. With respect to LEO products, automotive grade components are used primarily for both passive and active components. Active components will have radiation testing and analysis performed for various exposures such as Ionizing radiation (TID), non-Ionizing radiation (TNID), neutron displacement damage (NDD), and single event effects (SEE) from heavy ions or protons. For SEE testing, depending on the type of active component, there are various tests performed to evaluate the component for transients (SET), latchup (SEL), single event upset (SEU) are a few of the many tests performed for SEE. These are tested for both destructive and non-destructive effects. For any behavior that is not typical, this information is then used to analyze the potential impact to the oscillator and ultimately the system level impact.
Q. Space systems can operate in harsh thermal, mechanical, and radiation environments. What testing and qualification processes does Raltron perform to validate oscillators and frequency control components for these conditions?
Alexander Wolloch: We perform TID and SEE testing on the oscillator system level. A pre-radiation dataset is collected and then used to compare against the dataset that is taken post exposure. We also have performed radiation testing on individual components and analyzed on the component level the potential effect on the oscillator. From a component level standpoint, the individual component datasheet is used to validate the effects of radiation exposure. Any deviations from these parameters are then simulated in the circuit that uses that specific component.
Q. Do your space-capable products have flight heritage or deployment history in programs involving NASA, ESA, military, or other aerospace organizations?
Alexander Wolloch: No, we are primarily focused on commercial LEO products at this time.
Q. Does Raltron maintain a dedicated portfolio of pre-qualified space products, or can customers select from your broader oscillator range and request qualification for mission-specific requirements?
Alexander Wolloch: Our space products are typically qualified on a lot-to-lot basis with respect to radiation testing and environmental qualification. We use this approach due to customers having different requirements. If a particular program has similar radiation requirements as our standard testing, we can certainly use our standard space products to reduce lead time for the customer.
Q. The rapid growth of LEO satellite constellations has introduced new commercial approaches to space hardware procurement. Many LEO systems use components that are not traditionally space-certified. What is Raltron’s view on qualification needs for LEO missions?
Alexander Wolloch: Through testing and analysis, the use of commercial-off-the-shelf (COTS) components has become a growing trend in the industry. The high cost and long lead times of traditional radiation hardened devices are not advantageous for LEO constellation for manufacturers. Typically, LEO satellites have a shorter mission duration, and the payload is significantly less expensive than a GEO satellite with a 20+ year mission life. We still perform many of the same environmental tests such as shock, random vibration, thermal shock, thermal testing and burn-in that traditional radiation hardened components endure, however the cost and lead-time is significantly less.
Q. How do oscillator requirements differ between traditional GEO/MEO satellites and newer LEO constellation platforms?
Alexander Wolloch: GEO/MEO satellites have a significantly longer mission duration which impacts radiation exposure levels and also some oscillator performance parameters such as aging. Other metrics such as output power stability over time and radiation are also not typically found in LEO products. With that said, many of the LEO products have equivalent or improved performance over their GEO/MEO counterparts with respect to phase noise, frequency vs. temperature and steady state power consumption.
Q. What are the most important performance parameters satellite designers evaluate when selecting oscillators for space applications such as phase noise, stability, aging, radiation tolerance, or power consumption?
Alexander Wolloch: All parameters listed are critical to the performance of the satellite. Frequency errors from aging or temperature generate system errors for various satellite systems which impact performance for synchronization, communication and data transmission. Phase noise, which is a critical parameter for most oscillators space or commercial, can impact digital communication systems by increasing bit error rate (BER), reduce receiver sensitivity, impact local oscillator (LO) performance, degrade carrier signals and reduce carrier tracking ability to name a few. Power consumption is also critical to understand, especially with OCXOs. Typically, heat is required to be pulled away from components with heatsinks or heat pipes, however an OCXO needs to heat the quartz crystal to its turnover point for optimum performance. If the system integrator uses an aggressive heatsink on the OCXO, it can cause the steady state power to increase dramatically. The same can also be said without a heatsink. The power generated internal to the OCXO cannot escape and therefore will cause the oven to shut down prematurely. Characterizing the OCXO thermal impedance is important for any system designer so that these effects are avoided.
Q. Beyond oscillators, does Raltron provide other RF or frequency control components for satellite payloads and communication subsystems? How do these complement your oscillator offerings in space designs?
Alexander Wolloch: Currently we are focused on providing the highest level of quality and performance for our space OCXO portfolio, however in the future we are looking to develop modules that integrate our OCXOs with space qualified PLLs, frequency multipliers and GPS disciplined OCXOs. These would be available as individual modules or as an integrated assembly capable of running from the spacecraft 28V bus.
Q. Looking ahead, how do you see oscillator and timing requirements evolving as satellite architectures become more software-defined, higher throughput, and increasingly deployed in large constellations?
Alexander Wolloch: Regardless of the architecture, oscillators will be a critical component even with software-defined radios (SDR). An oscillator is still used for conversion with a mixer for baseband and IF frequencies. Timing and synchronization for metrology also requires a stable clock source.
About Alexander (Sasha) Wolloch
Alexander (Sasha) Wolloch is the Founder and CEO of Raltron. He holds an electrical engineering degree from Ecole Supérieure d'Électricité (1976) and an MBA from the University of Paris (1978). Sasha began his career at ITT as a design engineer, later moving to the U.S. to manage technical marketing for its crystal and oscillator products. He founded Raltron in Miami in 1983 and has since grown it from a small start-up into a global electronic component supplier serving numerous Fortune 100 companies. Most recently, he has driven the company’s expansion in Miami, Fl designed and produced high performance OCXOs for telecommunications, high end instrumentation and LEO satellite applications.
