FREQUENTLY ASKED QUESTIONS

Powercast develops wireless power and RF energy harvesting solutions to provide power-over-distance for low-power applications (low microwatts and low milliwatts). Devices that typically operate on batteries for months or years can benefit from Powercast’s patented, high-efficiency RF energy harvesting technology. The cost of wiring or battery replacement can be eliminated in low-power devices through wireless, remote trickle-charging, or devices can be made completely battery-free.

General Questions

What are the intended applications for Powercast technology?

Many applications can benefit from Powercast’s RF-based long-range power-over-distance wireless charging technology. The amount of received power, the use case, antenna form factor, and charge rate must all be considered.
Low-power applications include high-function RFID sensor tags for environmental monitoring, battery recharging for wearables and other consumer devices, batteryless price tags that retailers can update electronically with UHF RFID readers, smart cards that can recharge while in use when near NFC POS readers or RFID readers, and LED-based illuminated packaging.  Smart, configurable, and controllable, Powercast’s wireless power technology can automatically activate when devices need charging and turn off when they’re done, or can deliver power continuously or on a scheduled basis.
The company has helped customers solve remote wireless charging challenges in the industrial, commercial and military markets since its Powercaster transmitter was FCC approved in 2010, and is now helping consumer electronics manufacturers do the same with its PowerSpot transmitter that was FCC approved in 2017.

How does Powercast’s RF power harvesting technology work?

A tiny Powerharvester® receiver, embedded in systems or devices, harvests RF energy sent over the air from either a dedicated transmitter, such as Powercast’s Powercaster or PowerSpot, or from anticipated RF sources such as UHF RFID readers or NFC POS readers. The embedded Powerharvester then converts the RF to DC to either directly power that batteryless device or recharge its batteries.

Where can I buy Powercast products?

Powercast technology is designed for Original Equipment Manufacturers (OEMs) to embed directly in their products and systems. Powercast products can also be purchased through our distributors, Mouser and Arrow Electronics. If your company is an OEM and is seeking sales support, please contact us at sales@powercastco.com to discuss your application in more detail.

What products does Powercast offer?

Powercast offers a wide range of products including Powerharvester chips and modules, evaluation tools, antennas, transmitters, batteryless and rechargeable sensor tags, and more.
Our modules, the P1110B and P2110B, are for low volume applications and provide ease of implementation. Our chipsets, the PCC110, PCC114 and PCC210, are for high volume applications. Additional information about the chipsets is available after the completion of a Reference Design Confidentiality Agreement. Please contact Powercast directly for more information.

Does Powercast engage in custom development projects?

Yes. Powercast frequently engages in custom development projects related to RF-based wireless power and RF energy harvesting. Please contact us with details on your project and we will be happy to provide a quote.

Where can I get more info about the Powerharvester chipset?

Basic information about the PCC110, PCC114 and PCC210 chips is available here.  More detailed information is available after the completion of a Reference Design Confidentiality Agreement.

Consumer Charging Questions

Can Powercast charge mobile phones?

 Yes, Powercast’s RF technology is absolutely capable of charging mobile phones over the air. However, our new PowerSpot transmitter targets phone and computer peripherals for now. At CES 2018 we showcased mobile phone charging as a technology demonstration two ways: 1) Phone case recharging using our PowerSpot transmitter and 2) Qi phone charging with Qi integrated into our PowerSpot. Future Powercast product releases will target direct mobile phone recharging while addressing consumer expectations like charge time, product size, and cost.

Can you describe the difference between far-,mid-, and near-field wireless power transmitters?

There are two field regions: the near-field and the far-field. The exact boundary is debated by various types of engineers (antenna, EMC, etc.). Powercast defines the boundary as a distance of 2D2/λ where D is the largest dimension of the transmitting or receiving antenna and λ is the free space wavelength. The near-field can be divided into two sub-regions: the reactive near-field and the radiating near-field (sometimes called the transition region). The term Mid-Field is a marketing term and likely refers to one of the near-field regions. The far field is when the RF waves begin to travel away from the antenna into the air. Powercast transmitters are far-field transmitters but can operate in the near field as well, so exact definitions become less important.

Can you expand on the FCC’s current regulations governing devices such as RF transmitters?

The FCC must bless any wireless technology as safe, and non-interfering with authorized telecommunications. There are two sections of the US Federal Code of Regulations that regulate RF transmission devices – Part 15 and Part 18. Part 15.247 limits both the transmitter’s output power and antenna gain. In general, transmitters operating in the 915 MHz frequency band, like a PowerSpot transmitter, along with 2.45GHz and 5.8GHz transmitters, may output up to one watt of power to the transmitting antenna (under certain conditions). Typically, this requires using an antenna with a gain of 4 (6dBi) or less. This limits the output power to 4W EIRP (output power multiplied by antenna gain). Powercast’s first, general-purpose TX91501 Powercaster® Transmitter and new TX91503 PowerSpot® Transmitter are certified under Part 15.247. Part 18 regulates Industrial, Scientific, and Medical (ISM) equipment. Typical ISM applications are the production of physical, biological, or chemical effects such as heating, ionization of gases, mechanical vibrations, hair removal and acceleration of charged particles. Part 18 requires that the transmitter generate and use the RF energy locally. Powercast has also obtained approval under Part 18 in the past for several specific products.

Can you tell us more about the household consumer companies you're working with?

Unfortunately, we have confidentially agreements with the majority of our customers. The referenced customers are household consumer names and we are actively working with them and others to integrate our technology and chips into their devices and wireless charging ecosystems. As you would expect, public product announcements will not occur until they are ready for sale on the market, which we are expecting later in 2018 or early 2019.

Are there plans to expand the PowerSpot transmitter into other regions?

Yes, the PowerSpot transmitter is currently approved in the US and Canada. We are actively working on two other designs of the PowerSpot transmitter to support Europe and Asia.

You mention that Powercast’s technology has capabilities beyond today’s permitted standards. What's next?

Powercast continues to provide our customers viable, practical solutions that meet governmental regulations. In 2006, we helped the military develop and deploy a wireless power application where a moving receiver required over 5W of continuous output power and a recharging range of over 20 feet. However, current regulations do not allow that level of transmission power or the high-gain beam steering antenna that was used. See FAQ #3. Powercast will continue to align its product roadmap with current and planned regulations

Where are your transmitter’s FCC and ISED (Canada) approval details?

You can obtain our FCC details by searching our FCC ID, YES TX91503, here. You can obtain our ISED details via our IC ID, 8985A-TX91503, here.

Power Questions

How much power can be transmitted?

Regulations in the United States and Canada limit the amount of transmittable power. Under the FCC Part 15, power is limited to 4 Watts EIRP, and both our Powercaster (TX91501) Transmitter and our PowerSpot (TX91503) Transmitter broadcast approximately 3 Watts EIRP each.

How much power is received?

The received power is determined by several factors, including distance and receiving antenna performance. Available energy after conversion in the low miliwatt and microwatt range should be expected. Please see the wireless power calculator available on our website: http://www.powercastco.com/power-calculator/

What is the efficiency of the power transmission?

Powercast’s technology enables unique applications for remote charging, and multiple devices can be charged simultaneously. The end-to-end efficiency of power transfer is not a relevant metric of comparison.

What is the efficiency of the RF to DC power conversion?

RF-to-DC conversion efficiency is as high as 75%. Please see the datasheets found on our Powerharvester Receivers page for performance graphs.

What is the maximum distance that your transmitter will work?

The transmitter output power is limited by government regulation, so the receiving antenna is a primary factor in operating range. Antennas with high gain provide a better range. The directional antenna provided with Powercast’s evaluation boards has a gain of 6dBi and will enable a range of 40-45 feet (12-14 meters) line of sight with the P2110B component. Our P21XXCSR-EVB Chipset Reference Design Evaluation Board has newer designs that enable greater sensitivity and range.

Radio Frequency Questions

What frequencies are supported?

The P1110B and P2110B Powerharvester receivers are designed for a center frequency of 915 MHz, but have a reasonable operating range from 850-950 MHz. The P21XXCSR-EVB supports GSM-850 uplink, Europe RFID and GSM-850 downlink, ISM USA and GSM-900 uplink, GSM-1800 uplink, GSM-1900 uplink, and Wi-Fi 2.4 GHz frequency bands. Please see the datasheets on our Powerharvester Receivers page for performance details. The Powerharvester technology can be adapted to other frequencies and Powercast does custom development projects for frequency modification. Please contact us to discuss such custom projects.

Can I use P1110B and P2110B components for harvesting Wi-Fi?

These components are designed with a center frequency of 915 MHz and therefore cannot be used to harvest energy from Wi-Fi routers. Although these components cannot be used to harvest Wi-Fi our P21XXCSR-EVB Chipset Reference Evaluation Board does support harvesting Wi-Fi 2.4GHz frequency.

Do you have any modules for harvesting from 2.4 GHz/Wi-Fi?

Currently, the P21XXCSR-EVB Chipset Reference Evaluation Board supports harvesting from Wi-Fi 2.4 GHz frequency. However, standard modules for harvesting 2.4GHz are not offered at this time. Please contact us about using the PCC110 and PCC210 chips for harvesting Wi-Fi.

Antenna Questions

What types of antennas can be used?

Powerharvester receivers are designed to work with standard 50-ohm antennas. An antenna should be matched as closely as possible to the frequency being received.

Does Powercast design custom antennas?

Yes. Powercast has antenna design expertise. Please contact us to discuss custom antenna development projects.

Transmitter Questions

Can I make any adjustments to your transmitter?

There are no user controls on the existing Powercaster (TX91501) Transmitter. The PowerSpot (TX91503) allows the user to turn it on or off. Making modifications inside of the device would be a violation of FCC and Industry Canada (ISED) regulations and would also void the product warranty.

Is your transmitter required for Powercast’s technology to work?

Dedicated Powercast RF transmitters (such as the Powercaster or Powerspot) are not required to operate the Powerharvester receivers, but some other source of RF energy must be provided. The Powerharvester receivers can harvest enough energy to power themselves when near an anticipated RF source, such as a UHF RFID reader or NFC POS reader. Ambient energy from sources such as mobile base stations (i.e. cell sites) are typically not strong enough to operate existing Powerharvester receivers at a useful distance, but may apply in some scenarios. Harvesting from a mobile phone is typically more viable than harvesting from a mobile base station.

Can I use your transmitter in any country?

Both Powercast’s Powercaster (TX91501) Transmitter and PowerSpot (TX91503) Transmitter are certified for use only in the United States and Canada; other countries have different frequency requirements and power limitations. Powercast is actively working on other designs to support Europe and Asia. Some countries allow for demonstration or experimental use without regulatory certification.

What modulations can be used to operate the Powerharvester receivers?

The Powerharvester receivers work independent of the type of modulation used (FHSS, DSSS, etc) by a transmitter, and can receive power from one or more transmitters using any type of modulations. The power of the signal is the primary metric for operation.

How does your transmitter send data?

Both the Powercaster (TX91501) Transmitter and PowerSpot (TX91503) Transmitter broadcast data as well as power. The data is currently a transmitter ID implemented using 8 bits. Future versions may include a timing broadcast for network synchronization. The data is sent using Amplitude Shift Keying (ASK) modulations and is recovered through the Powerharvester receiver in conjunction with external circuitry and a microcontroller. The data is factory-set and not user adjustable.

Will your transmitter interfere with other RF devices (Cell Phones, Wi-Fi routers, etc.)?

All devices that generate RF frequencies have the potential to interfere with other RF devices. The interference potential is dependent on numerous factors including the field strength of the unwanted signal, the frequency band of operation, and the ability of the receiver to reject the unwanted signal. The Powercaster Transmitter is FCC approved as FCC ID: YESTX91501 and Industry Canada(ISED) approved as IC: 9895A-TX91501. The PowerSpot Transmitter is FCC approved as FCC ID: YESTX91503, and Industry Canada (ISED) approved as IC: 8985A-TX91503. The 915 MHz output power is approximately 0.5w (3W EIRP) and uses Direct Sequence Spread Spectrum (DSSS) to spread the power over more than 500 kHz as required by the FCC and IC. The Powercast DSSS signal allows devices to more easily reject the Powercast signal. Powercast has done empirical testing with mobile phones, Wi-Fi devices, and 915 MHz transceivers and found no degradation in device performance at practical separation distances.

How much power does your transmitter use?

The TX91501 Powercaster Transmitter and TX91503 PowerSpot Transmitters draw about 2.5W of energy from a wall outlet, which is less energy than a typical night-light. It would take 40 transmitters to have the same total power as a single 60W light bulb.

Technology Questions

Is Powercast technology patented?

Yes. Powercast technology is covered by numerous patents. The company’s growing IP portfolio currently includes 46 patents worldwide (21 in the US) and 30 patents pending.

Is Powercast technology safe?

Absolutely. Powercast technology is approved for use in the United States and Canada. Our technology is based on radio waves that are also generated by many commonly used devices, including mobile phones, cordless phones, wireless sensors, security system, etc. RF energy declines as the inverse square of the distance from the transmitter, meaning it declines rapidly. A typical mobile phone user will receive far more RF energy from their own mobile phone than they will from a properly installed Powercast transmitter.

Can Powercast transmit power through walls or other obstructions?

Yes. Radio waves pass through many types of materials, including walls. Walls and obstructions attenuate (absorb) radio waves, and this will slightly reduce the amount of energy available for reception. Radio waves reflect off of metal walls which greatly reduce or prohibit power transfer.

How does Powercast technology compare to induction-based charging solutions?

Typical induction charging solutions like charging pads and electric toothbrushes require that the power source and receiving device be in very close proximity to one another to transfer power efficiently, usually within millimeters, which is essentially zero distance. These types of solutions typically require special alignment and charging pads or cradles. Powercast’s RF-based technology provides power-over distance to one or more devices and does not directly compete with induction-based charging technologies.