PTCRB certification is a critical step for any cellular device destined for the U.S. and Canadian markets. Failing these tests - particularly those required by AT&T, Verizon and T-Mobile can delay product launches and drive up costs with repeat certification attempts. One of the most common causes of failure can come from the antenna integration.
That’s where Inpai (P/N SR4L099), Antenova’s newly developed SMD antenna, changes the game - meeting PTCRB requirements with ease and enabling engineers to create smaller, more compact cellular devices without compromise.
More than just another 4G/LTE antenna, Inpai is a purpose-built solution that delivers sufficient performance to pass PTCRB certification even on reduced 100mm/110mm length ground planes giving a 20% size reduction compared to typically 120mm or more for standard cellular antennas.
Why PTCRB Certification Often Fails
In the U.S., the cellular network must be chosen and certification by the network operator is required for every cellular device before it can connect to mobile networks like AT&T, Verizon, or T-Mobile. The PTCRB certification (network approval) ensures that cellular devices operate with strong performance, which helps to extend the coverage area of the network. But it’s also where many IoT designs fail, often due to poor antenna integration, which doesn´t provide enough antenna efficiency to pass the PTCRB requirement specification of chosen network operator.
For design engineers, the challenge begins with choosing the cellular network early in the development phase. That decision dictates the technical requirements the antenna must meet, particularly in the low bands below 1GHz (B12, B13, B5) where each network operator in the US have slightly different requirements stated as TRP levels for their PTCRB requirement specification, and the higher bands (B2, B4).
Antenna Efficiency to meet TRP Requirements Across U.S. & Canadian Carriers
| TRP (dBm) | B12 | B13 | B5 | B4 | B2 |
| AT&T | 18 | 18 | 18 | 20 | 20 |
| Verizon | 18 | 18 | 20 | 20 | 20 |
| T-Mobile | 18 | — | — | 20 | 20 |
The required performance is measured using TRP (Total Radiated Power). For example:
- Low bands for AT&T (B12, B13, B5) or for Verizon (B12, B13) and for T-Mobile (B12) require ≥18dBm TRP, which translates to ≥31.6% antenna efficiency.
The required antenna efficiency is calculated by subtraction of the antenna radiated power from the transmit power of the cellular modem. In this case of 18dBm TRP requirement, the formula is 23dBm-18dBm=5dBm loss. Then 5dBm is converted to a percentage efficiency: 10-5/10 = 31.6%. Therefore, the antenna must have an efficiency of ≥31.6%.
High bands (B2, B4) and Verizon´s Low band (B5) require ≥20dBm TRP, translating to ≥50.1% antenna efficiency by using the same conversion method as above.
And that’s for standard-size devices. AT&T’s SFF (Small Form Factor) offers a requirement for small devices with a lower transmit power. This permits the antenna to have reduced efficiency and still meet AT&T’s carrier certification. It allows smaller devices, including the plastic case (<107mm) to qualify with relaxed TRP levels for a SFF device as low as ≥12dBm TRP for bands (B2, B4), or 8% antenna efficiency, and ≥10dBm TRP for band (B12), or 5% antenna efficiency.
As seen in the measurement table below showing Inpai performance on various ground plane sizes across critical cellular bands, at Antenova we have engineered Inpai antenna to provide reliable performance and efficiency on smaller ground planes enabling compliance with U.S. network operators like AT&T, Verizon, or T-Mobile, enables developers to design smaller products without the trade-offs most SMD antennas suffer from.
Engineering Tips: Designing for PTCRB Success
To help design engineers integrate Inpai successfully and pass PTCRB certification, here are five key tips to be followed:
- Always position the Inpai antenna at the end of the PCB
- No shortening of the recommended ground plane length
- Use of suggested matching components for the Inpai antenna specified in datasheet
- Optimization of matching once the design is finalized
- Consideration of device size limits based on ground plane size
The Inpai - Engineered for Compact IoT Designs
Inpai has been engineered from the ground up, designed specifically for 4G/LTE devices targeting the U.S. and Canadian markets, Inpai offers:
- Reliable performance on compact ground planes of 100mm/110mm length, that’s a 20% size reduction compared to typically 120mm designs.
- High efficiency across critical cellular bands, enabling compliance with AT&T, Verizon, and T-Mobile.
- Compatibility with standard and SFF certification schemes.
- Proven integration success through pre-certification RF testing and design support from Antenova. Antenova helps customers to prepare for PTCRB testing, by reviewing the design, and carrying out RF testing in an anechoic chamber.
This makes Inpai the No.1 choice for design engineers who need to shrink device size while passing operator requirements on the first try. Compared to the majority of cellular SMD antennas on the market, Inpai provides a unique blend of compact form factor and performance compliance - eliminating the most common cause of certification failure from day one.
Get Started with Inpai Today
Avoid costly certification failures and build smaller, market-ready cellular devices with Inpai.
Visit the product page to download the datasheet, request samples, or speak with our RF engineers.
Explore the Inpai Antenna: https://www.antenova.com/product/inpai/
