Quote

Table of Contents

Antenna‑in‑Package (AiP): The Key to High‑Performance Wireless in 5G & 6G

Recently, wireless technology has developed at a rapid pace. This has meant that not only the realization of 5G technology but also the initial steps towards the realization of 6G technology have been made. It is in this context that the requirements for antennas and RF components have also become challenging. It is in this context that one of the enablers for achieving the requirements for modern wireless communication systems is the concept of Antenna in Package (AiP). In the following content, the following aspects are discussed:
 
  • Grasp the concept of AiP and why it is different from traditional PCB-based antenna technology.
  • Investigate the band of frequency associated with AiP technology.
  • Grasp the concept and idea of Antenna-in-Package and associated architectures and integration.
  • Identify key design considerations and challenges for PCB and associated packages in 5G and 6G.
  • Identify key material considerations and associated substrates.
  • Identify layout considerations for PCB, SiP, and AiP in 5G systems.
  • Project future developments in wireless communication systems.
antenna in package(AiP)

What is Antenna-in-Package (AiP)?

Traditionally, antennas are designed and fabricated either as individual components or integrated on the PCB and then interfaced with the RF front-end chip using long traces and connectors. This approach is well proven, but it is also known to introduce issues of signal loss, noise, and complexity, especially in millimetre wave (mmWave) 5G technology.
 
The Antenna-in-Package technology removes all of these issues by integrating one or more antennas in the chip package. This is achieved by placing the antenna elements and RF transceiver either inside the package substrate or on its top surface, thus minimizing the length of the interconnects.

AiP Frequency Range: From Sub‑6 GHz to Sub‑THz

Furthermore, AiP is not limited to a specific frequency band. Instead, its operating band covers all the existing and future wireless standards. Here are the frequency bands in detail:
 
  • Sub‑6 GHz (FR1): In this band, the 5G layers are included. AiP technology is not widely used in this band due to the capability of traditional PCB antennas to provide reasonable performance. However, it may be seen in extremely compact devices where space is extremely scarce.
  • Millimetre‑wave (FR2): This type of wave is where the AiP solution can work best. In this band, several frequency bands, including 24 GHz, 28 GHz, and 39 GHz, along with the 60 GHz unlicensed band, benefit significantly from the feature of Antenna-in-Package that ensures minimal interconnect losses. Even a few millimeters of loss in the interconnects may lead to performance degradation. Hence, the almost zero distance between the antenna and the transceiver becomes inevitable.
  • Sub‑THz (100 GHz – 300 GHz): In this band, the research on the development of 6G technology is being conducted. Hence, the use of AiP becomes inevitable. In this band, the wavelengths are reduced to the millimeter or even submillimeter scale. Hence, the antenna elements may be placed within the package.

AiP Structures and Integration Technologies

The term “AiP” does not refer to a single implementation but rather to a family of packaging approaches. The choice of the structure also determines the expense, performance, and ease of manufacture.

Package Architectures

  • Organic Substrate AiP: This is based on materials like ordinary PCB materials, i.e., BT, ABF, etc. Organic substrate AiP is low-cost and predominantly used in consumer applications like smartphones, wearables, etc.
  • LTCC (Low-Temperature Co-Fired Ceramic) AiP: This offers excellent thermal performance and good control of the dielectric material. This is used for highly efficient applications like automotive radar and infrastructure applications.
  • Glass-Based AiP: This is being developed for sub-THz applications. This material offers very low loss and excellent dimensional stability, enabling extremely small feature sizes.

Integration Approaches

  • SiP (System-in-Package): AiP technology can also be used to integrate it into an even larger SiP, which also contains the RF transceiver, power management, and sometimes even baseband processing. This multi-chip integration saves board space and makes the system design easier.
  • FCBGA (Flip-Chip Ball Grid Array): In FCBGA, several high-performance AiP modules are encapsulated in a Flip-Chip Ball Grid Array package. Flip-chip mounting minimizes parasitic inductance, and the Ball Grid Array interface offers a strong connection to the main PCB. FCBGA is used in communication infrastructure, test equipment, and high-end consumer applications.

Leaded vs. Lead-Free Antenna-in-Package

Environmental regulations such as the RoHS directive have forced the industry to adopt lead-free solder joints. This has led to a trade-off.
  • Lead-free AiP: This is a requirement for consumer and commercial applications. Lead-free solders such as SAC have good performance characteristics but require good process control, particularly with larger BGA components with fine pitches.
  • Leaded (or hybrid) AiP: This is still present in applications that require high reliability, such as the aerospace and defense industries and car safety systems. These solders provide good resistance to damage from temperature changes.
 
When selecting an AiP module, the level of stringency of the environmental regulations and the level of reliability required by the end product need to be weighed.

Key Benefits of Antenna-in-Package

  • Minimal Signal Loss: This occurs when the chip is close to the antenna. This reduces unwanted electrical effects, hence reducing signal loss.
  • Small Form Factor: Antennas within a package provide more space on a PCB. This enables engineers to increase the number of features available on a device.
  • Increased Performance: This improves impedance matching as well as coupling. This improves RF performance in general.
  • Selective Assembly: This uses fewer components. This reduces complexity, hence speeding up production.

Where Antenna-in-Package is Particularly Useful?

The working regions for 5G networks are sub-6 GHz and mmWave. The frequency bands for these are 24 GHz, 28 GHz, and 39 GHz. At these frequency bands, even a small amount of conductor in the trace can cause significant loss. Antenna-in-Package solution resolves this by physically placing the antenna in close proximity to the transceiver.
The application domains for AiP PCBA are as follows:
 
  • Beamforming and Massive MIMO: A large number of antennas are required for the transmission and reception of directions for 5G and 6G. This can be achieved through a highly integrated solution similar to Antenna-in-Package.
  • Miniaturised Consumer Devices: AiP is a space-saving technology. The following are the consumer devices that benefit from AiP technology: smartphones, IoT devices, AR/VR, and smartwatches.
  • Automotive Radar: AiP solution is employed in radar modules operating at 77 GHz and 79 GHz to achieve high performance levels.
  • Satellite Communications: In user terminals for LEO satellite communications, flat panels employ AiP PCBA to be low in profile and high in performance.

Material Selection in Antenna-in-Package

For Antenna-in-Packages operating in the mmWave frequencies, performance directly relates to material selection. Therefore, performance trade-offs include electrical performance, thermal resistance, and cost.
 
  1. Substrate Technologies
    • Organic Substrates (BT, ABF): Affordable options, best suited for consumer electronics.
    • LTCC (Low-Temperature Co-Fired Ceramic): Offers thermal and frequency reliability, best suited for high-end devices.
    • Glass and Fan-Out Packages: Low signal loss and routing accuracy make them best suited for sub-THz applications.
  2. Electrical Requirements
    Low dissipation factor (<0.005) and constant dielectric constant (>3) are essential to maintain signal quality at high frequencies.
  3. Mechanical Compatibility
    Matching the coefficient of thermal expansion between packages and PCBs eliminates warping during temperature changes.
Antenna in Package on PCB

Design Strategies for AiP PCB Integration

Following the selection of the material, the design stage is aimed at achieving signal integrity, radiation efficiency, and system-level integration.
 
  • Maximize Package‑to‑PCB Interface The connections from the AiP module to the PCB should be as short as possible. This is achieved by minimizing vias, using controlled impedance, and providing direct grounds to reduce signal loss and improve transitions.
  • Optimize the PCB Stack‑Up The stack-up should be optimized to have separate RF layers, an RF ground plane, and low-loss dielectrics. LCP, PTFE, and advanced glass substrates are best for stable performance at high frequencies.
  • Phase and Length Matching In beamforming and phased set AiP modules, all the feed traces should be equal in length to keep phase relationships accurate across antenna elements.
  • Clean Layout Around the AiP No high-speed digital signals should be placed near the AiP module, and there should be space to allow the antennas to radiate properly.

Challenges in Antenna-in-Packages PCB Design

However, there are some pitfalls associated with integrating AiP PCBA, which if not addressed appropriately may prove fatal.
 
  • EMI and Isolation Since the antenna will be in close proximity to digital circuits, there are likely to be interference issues. Techniques such as grounding, shielding (ground via fences, metal cans), etc. need to be employed appropriately.
  • Manufacturing Complexity and Cost Technologies such as FOWLP, LTCC, or high-density organic substrates are complex. They require very precise manufacturing tolerances. This needs to be taken care of by engineers during the design phase.
  • Material and Mechanical Constraints Even when working with low-loss materials, dielectric property variations and CTE mismatches need to be taken care of. A good choice of materials along with mechanical designing will ensure long-term reliability of the product.
  • Operating at such high frequencies generates a lot of heat. To cool down, there needs to be appropriate provision of thermal vias, copper coin inserts, or a direct interface to the chassis.
  • Test and Calibration
    Testing AiP modules is not as simple as testing discrete antennas. Over-the-air testing needs to be performed. This needs to be included in the design phase itself. Design-for-test (DFT) needs to be included at the beginning of the design phase.

AiP Technology for 6G and Beyond

As 6G research goes into sub-THz frequencies (100 GHz +), antennas will become even smaller, and Antenna-in-Packages (AiP) and Antenna-on-Chip (AoC) technologies are the next logical step. Future-generation AiP modules will leverage:
 
  • Glass or polymer substrates for ultra-low loss.
  • Integrated beamforming ICs in multi-chip packages.
  • Smart AiP modules with reconfigurable antennas and AI-assisted tuning.
  • Panel-level packaging (PLP) to reduce cost and facilitate mass production.
  • Heterogeneous integration combining III‑V compound semiconductors (for power amplification) with silicon (for beamforming) in a single AiP module.
 
These innovations will pave the way for ultra-high-speed wireless linkages in autonomous systems, AR/VR, satellite communications, and intelligent IoT networks.

Conclusion

Antenna in Package (AiP) is considered to be one of the key technologies for the next generation wireless world. Antenna in Package eliminates the electrical and physical limitations associated with ultra high frequency designs by combining the RF circuit and the antenna in a single package. This results in smaller, faster, and more efficient executions. The key to success for RF and PCB designers in the world of 5G and 6G lies in efficient co-design at the right time, efficient material selection, and seamless integration at the chip, package, and board levels.
 
For the future of super-fast wireless communications, Antenna in Package is not only the key to the breakthrough but also the key to the way the world will be connected in the future. If you are looking to turn your Antenna in Package design into a working product, then please request a trustworthy PCB manufacturing quote from FS PCBA.

FAQs about Antenna-in-Package

Since the antenna and RF circuits are combined in packaging, AiP modules are harder to repair or replace in the components. Replacing the entire module is required in most failures, although more recent module-based AiP approaches attempt to make them more serviceable and recyclable.
Yes. Many AiP designs now include tunable antennas or switchable components to cover distinct regional 5G bands. That allows a single hardware platform to cover multiple markets with minimal redesign.
AI is optimising antenna geometry, making predictions for performance, and reducing simulation time. Future AiP modules may even use AI-driven tuning to automatically adjust to changing environments for better signal quality.
Yes. Because AiP modules are close to the surface of the device, engineers go out of their way to control radiation patterns to meet Specific Absorption Rate (SAR) standards. Smart beamforming and shielding allow for safe user exposure without sacrificing strong connectivity.

Get a quote

Related Blogs