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A fabless RF GaN company offering innovative RF energy solutions and supporting telecommunication and defense RF GaN markets – An interview with WAVEPIA

Over the last few years, the radio frequency (RF) industry has received a boost from the implementation of GaN technology. GaN is the main driver in telecom and defense applications, thanks to its robust power output at high frequencies and its small footprint. As reported in GaN RF Market: Applications, Players, Technology and Substrates 2020, the overall GaN RF market is expected to increase from $740M in 2019 to more than $2B in 2025.

The arrival of 5G in the telecom infrastructure will see an increase in the number of active antenna systems (AAS) and an increase in bandwidth, which will favor GaN’s implementation. In military applications, due to the increase of T/R systems in airborne radar, GaN devices are replacing bulky traveling wave-tube (TWT) -based systems, ensuring that defense will remain one of the GaN market’s main drivers. For RF energy, innovative solutions are needed for GaN to compete with Si LDMOS systems. WAVEPIA, a fabless RF GaN company, offers cutting-edge GaN systems for RF energy, along with GaN transistors that support the growing telecom and defense markets.

Yole Développement recently met with Sanghun Lee, CEO of WAVEPIA, to discuss WAVEPIA’s technology status and the company’s roadmap for the coming years. This interview was conducted by Ezgi Dogmus, PhD., Compound Semiconductors & Emerging Materials Technology & Market Analyst at Yole Développement.

Ezgi Dogmus (ED): Could you please briefly introduce our readers to WAVEPIA and its history? What is your business model and why did you choose it?

Sanghun Lee (SL): WAVEPIA is an IC design house and fabless company in South Korea, established in 2014. Since starting the business, we have focused on building up our own product lineup. As a result of our efforts, we now have a solid lineup with GaN transistors (bare-dies, packaged transistors, and MMICs), inspiring us to expand our business boundaries into GaAs and RF energy solutions.
In terms of business model, we have a different one for each market. For the telecommunication and defense markets, we decided to support them with transistors only to prevent conflicts with our customers. In the GaN market, customers and suppliers have been suffering from a problem that they eventually ended up being competitive. For this reason, we only support the GaN market with sample modules for evaluation purposes for our transistors. In the RF energy market, we have a different business model. Since our RF energy solution, called HPGP (High-Power GaN Phase-Locked Loop), is the cutting-edge technology (no drive amplifier required) in the field, it caused us to be involved in the market and provide our efficient solution.

ED: What is your product portfolio/product line/service?

SL: WAVEPIA has a broad and efficient GaN solution for a variety of fields.

WAVEPIA’s product lineup - Courtesy of Wavepia
WAVEPIA’s product lineup – Courtesy of Wavepia

* GaN bare-die

  • 0.45?m, 48V, DC-10GHz
  • 0.25?m, 28V, DC-20GHz
  • 0.15?m, <20V, DC-40GHz
  • 0.1?m, <15V, DC-70GHz

* GaN MMIC

  • 20W, 0.3-6.0GHz GaN MMIC
  • 50W, 14-18GHz GaN MMIC
  • 2W, 27.5–28.5GHz GaN MMIC
  • 12W, 27.0–32.0GHz GaN MMIC
  • 12W, 35.0–37.0GHz GaN MMIC
  • 12W, 39.0–41.0GHz GaN MMIC

* Packaged GaN transistors

  • L-band: Few~400W
  • S-band: Few~400W
  • C-band: Few~150W
  • X-band: Few~100W
  • Ku-band: Few~50W
  • Ka-band: Few~10W

* GaAs MMIC

  • WPSM0P91028AQ: 0.9-1.0GHz, 28°Analog Phase Shifter
  • WPSM206028AQ: 2.0-6.0GHz, 28°Analog Phase Shifter
  • WPSM809028AQ: 8.0-9.0GHz, 28°Analog Phase Shifter
  • WPSM0P91006DQ: 0.9-1.0GHz, 3-bit 90° Digital Phase Shifter
  • WPSM244006DQ: 2.4-4.0GHz, 6-bit 360° Digital Phase Shifter
  • WPSM406006DQ: 4.0-6.0GHz, 6-bit 360° Digital Phase Shifter
  • WPSM0P97006DAQ: 0.9-7.0GHz, 0.5dB LSB 6-bit 30dB Digital Step Attenuator

* RF energy solution (900-930MHz, 2400-2500MHz):

  • HPGP 10W/20W/30W
  • RF CW Signal Generator (HPGP+RF GaN or LDMOS Amplifier) 100/250/500

ED: What is the specificity/added value of your GaN RF products?

SL: Each WAVEPIA product has its own specificity. I will introduce packaging and RF energy solutions later in this interview, but I would like to first introduce a reliability monitoring function which is applied for all of WAVEPIA’s bare-dies.

* Reliability monitoring function

Cross-section view of WAVEPIA’s Packaged GaN Transistor - Courtesy of Wavepia
Cross-section view of WAVEPIA’s Packaged GaN Transistor – Courtesy of Wavepia

As technology advances in the telecommunications sector, it requires more precious functions for devices. Especially the reliability monitoring function, also called “self-healing”, which is already a standard feature for the 5G telecom industry.
A brief explanation of the function: first, we paid attention to the fact that the MTTF (mean time to failure) of the GaN device exactly matches its gate-channel temperature. We designed our bare-dies to be able to measure the temperature of the gate channel so that we could predict their MTTF in real-time.

Example of a 64-element (8 x 8) antenna array using WAVEPIA’s GaN transistors - Courtesy of Wavepia
Example of a 64-element (8 x 8) antenna array using WAVEPIA’s GaN transistors – Courtesy of Wavepia

ED: Which applicative markets do you target with GaN products/services?

SL: We are focusing on high-power and high-frequency products for each market because we definitely believe there are some applications in those fields that can take advantage of GaN’s characteristics. Here are the main target applications for each market we are dealing with.

  • Telecommunications:
    • Sub-6GHz 5G (3.4-3.8GHz, 4.4-5.0GHz, etc.)
    • mmWave 5G (27-32GHz, 35-37GHz, 39-41GHz)
    • L/S/C/X/W-band communications
  • Defense:
    • L/S/C/X-band communications & radar
    • X-band satellite
    • Ku/Ka-band seeker, radar, and communications, etc.
  • RF energy:
    • RF plasma light
    • – SSPA microwave oven
    • – RF CW generator, etc.

ED: In the RF energy market, there is a competition with cost competitive LDMOS and GaN products. In this context, what is the added-value of GaN-on-SiC products?

SL: In view of the present situation in the semiconductor industry, it seems that GaN products are less price competitive than LDMOS products. On the other hand, according to your last report, design houses and foundries will grow their business faster than IDM companies. We also expect in the same way that the number of GaN foundries will increase, causing severe competition. This will lead to improving their technology to make them a larger wafer, allowing them to provide their products at a lower price. I agree with the opinion that it will take a lot of time, however, I don’t intend to wait only for that. Therefore, we have developed a new packaging technology and RF generator (HPGP) architecture to increase price competitiveness by using our technology. With the help of our new packaging technology and HPGP, our transistor and RF generator price will decrease while maintaining reliable performance.

ED: In which RF energy segments can GaN-on-SiC achieve faster market acceptance? What is WAVEPIA’s position in this market?

SL: As we explained in the Yole report earlier this year, it is the RF GaN generator solution called HPGP (High-Power GaN PLL), which does not require driver amplifiers. Since we developed 20W and 30W solutions, this allows our customers to use a smaller number of GaN for their systems or applications, helping us to increase price/performance-competitiveness over other solutions. Price competitiveness may be the most distinctive feature, but PLL’s functional aspects also differ from other generators.

The basic functions are listed below:

1) RF output power monitoring system supported

  • RF power (FWD/RVS)
  • Temp./ voltage /current

2) VSWR tracking

  • Frequency tracking to find the VSWR min. point as output impedance changes 
  • Auto/manual supported

3) Power (gain)/phase/frequency

  • Power controllable (0-10dB, 1W resolution possible)
  • Phase controllable (0-360 degree, 1degree resolution)
  • Frequency controllable (ex, 2.4-2.5GHz, 0.25kHz resolution)

4) Soft start function

  • Specific power control for plasma light applications ** Controlling (by I2C & SPI interface)

All functions for technical/mechanical can be customized or modified according to the customer’s requests. We are able to develop an optimized solution for each application’s needs because we can design most of the components used in the solution.

ED: There is a fierce competition with LDMOS, GaN, and other semiconductor platforms with the upcoming 5G. What is your point of view for sub 6 GHz and mmWave applications, respectively? What is WAVEPIA’s position in this market? Being based in Korea, with a strong ecosystem in that area, is your market essentially in Korea? How is your market balanced worldwide? In which region do you see some good traction for your products?

SL: Currently, in the mmWave 5G market, GaN devices are applied from small relays by applying high-frequency, high-power advantages. In sub-6GHz applications, LDMOS has a price advantage at some frequencies below 4GHz, but GaN products are satisfied with the performance in the 4.4 – 5.0 frequency band. Rather than competing with the two devices, it is believed that they will preoccupy the market by dividing the applications and markets that highlight the strengths of each device.
In terms of WAVEPIA’s position, I think we play a very different role in each market. In the commercial telecommunications and defense markets, WAVEPIA is a startup company that is aggressively marketing and selling to enter the market. As major companies are already firmly established, we are striving to achieve entry through price and performance competition. On the other hand, HPGP, an RF solution provided by WAVEPIA in the RF energy field, is different from a simple power amplifier or signal generator provided by competitors. It has an innovative RF signal generator structure which provides an operating function that is essential to RF energy. With this technology, WAVEPIA leads the RF energy market without any competitors that stand out as a total solution company. For these reasons, we are working on various projects with many domestic or foreign companies, depending on each market and application. If I were to select one particular market that I’m interested in, it is the recent RF energy market in Asia. RF energy-related applications have been developed rapidly, which is expected to create a new market for household appliances.

ED: What kind of packaging is used for WAVEPIA’s GaN products? Does it vary for each applicative market?

SL: We apply the best packaging solutions for each transistor type: matched, unmatched, and MMIC.

One-package - Courtesy of Wavepia
One-package – Courtesy of Wavepia

On the right side of the figure is a picture and diagram of the hermetic package. It consists of an air cavity, ceramic lid, and GaN bare-die, and it requires wire-bonding to connect the air cavity to ceramic and to connect GaN bare-die to input and output. However, compared to the hermetic package, one-package developed by WAVEPIA does not require wire-bonding to the input and output by replacing them with the soldering method. The removal of these wires significantly reduces the assembly steps. Also, there is one more type of hermetic package which has via. Via can cause cracks due to the thermal expansion factor of ceramics and metals. However, by using the soldering method, WAVEPIA does not need this via either.
The one-package method allows WAVEPIA’s products to improve cost-competitiveness and performance as shown in image 4.

* WBL packaging for the Unmatched GaN Transistor

WBL package for the MMIC - Courtesy of Wavepia
WBL package for the MMIC – Courtesy of Wavepia

WBL, which stands for “wire-bonding less”, uses clip-bonding for GaN packaging instead of wire-bonding. With the help of this technology, we can manufacture automatically, leading to mass-production with great numbers.

* WBL packaging for MMIC

WBL package for the Unmatched Transistor - Courtesy of Wavepia
WBL package for the Unmatched Transistor – Courtesy of Wavepia

We also applied the WBL packaging solution to our MMICs, achieving great results even for higher frequency such as Ka-band and above. The development of packaging technologies has enabled us to package our products automatically, allowing us to increase output quantities at much lower prices. We were planning to introduce our new packaging automation machine at IMS2020, but it is a shame that it was postponed and will instead be held virtually.

ED: What is your target revenue for GaN-on-SiC RF technology in the next five years?

SL: It is difficult to reveal the exact figures we expect, but we could say we are looking forward to mass-producing the various projects we are currently working on either later this year or early next year. Of course, high profit-making is also important and we are aiming for it, but we hope that many of the projects we are participating in will get good results and that WAVEPIA will be a widely known brand.

ED: Could you please describe your product roadmap for GaN products in the coming years?

SL: We expect to keep expanding our business capabilities. We have a very interesting point of view for mmWave 5G FEM applications in the commercial market, high-power ku/Ka-band applications in the defense market, and no drive-amplifier HPGP, 50/100/250/500/750W (430MHz, 0.9-0.93GHz, 2.4-2.5GHz, etc.) in the RF energy market.

Interviewee

Sanghun Lee is CEO of WAVEPIA Co., Ltd, and a Deputy Chairman of Asia-Pacific for SSRFE, Solid-State RF Energy Section, at the International Microwave Power Institute. Prior to establishing WAVEPIA, he was a Senior Engineer at Samsung Electronics (ROK). He holds a PhD degree from Texas A&M University (USA).

Interviewer

As a Technology & Market Analyst, Compound Semiconductors, Ezgi Dogmus, PhD is member of the Power & Wireless division at Yole Développement (Yole).
She is daily contributing to the development of these activities with a dedicated collection of market & technology reports as well as custom consulting projects.
Prior Yole, Ezgi was deeply involved in the development of GaN-based solutions at IEMN (Lille, France). Ezgi also participated in numerous international conferences and has authored or co-authored more than 12 papers.
Upon graduating from University of Augsburg (Germany) and Grenoble Institute of Technology (France), Ezgi received her PhD in Microelectronics at IEMN (France).

Related report

GaN RF Market: Applications, Players, Technology and Substrates 2020
Driven by military applications and 5G telecom infrastructure, the GaN RF market continues growing.


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