May 16, 2019

What Are the Performance Implications of 3D Printing RF Components?

3d printing rf componentsUnless you’ve been ignoring news over the past decade, you’re probably aware of 3D printing and additive manufacturing. The low cost of simple 3D printing systems allows any college student to create basic parts and devices from readily available 3D mechanical models. When it comes to 3D printing RF components, however, more specialized additive systems are required to meet the performance goals of these functional products. This is especially true for institutions or companies involved in research and new product introduction (NPI), respectively.

With this in mind, designers must choose the appropriate additive manufacturing system for 3D printing RF components. Different systems are specialized for certain materials and have different tolerance limits on 3D printed parts, which inevitably affects the performance of the final product. With this in mind, the right additive manufacturing system can still provide several benefits for companies working on new electronics products.

An employee working with 3D printed RF components

You can 3D print embedded RF components with a unique form factor using the right additive manufacturing system.

Why Use 3D Printing for RF Components?

There are several reasons to consider using an additive manufacturing system to 3D print RF components. If you consider the range of available applications and the flexibility provided by an additive manufacturing system, RF component designers will have the ability to quickly tune, test, and optimize the design of new components to achieve high-performance applications that are the lightest weight and smallest physical volume possible.

In the defense and aerospace industries, outsourcing the manufacture of RF systems creates a potential security concern and sourcing concerns. Fabrication and assembly houses must be compliant with ITAR regulations, and they must be registered with the federal government in most cases.

In addition, these outside manufacturers will charge a premium for quick-turn, low-volume rapid prototyping runs. R&D and NPI for unique RF components require high precision, low-volume manufacturing runs. Thus, working with an outside manufacturer early in the ideation process is cost and volume prohibitive. Relying on an outside, traditional PCB manufacturer, will also incur significant lead times, especially when creating complex electronics structures, ultimately slowing down the R&D process.

These concerns can be easily resolved when your fabrication and assembly capabilities are kept in-house. Companies with these capabilities can print their own RF components in a day rather than weeks, in a single step process without additional machining or assembling. Keeping these systems in-house also alleviates security and compliance problems that arise when working with an external manufacturer.

The flexibility provided by additive manufacturing  does more than just alleviate sourcing, manufacturability, and security concerns. 3D-printed devices are not limited by the constraints of traditional manufacturing processes, giving designers the capability to design devices with unique geometries and capabilities. Designers can fine-tune the capabilities of their RF components without being limited by traditional PCB fabrication techniques, opening up huge potential for innovation in many sectors from consumer electronics to defense and space.

Control Over Frequency, Sensitivity, and Form Factor

Perhaps the most important aspect of designing RF components is tuning the operating frequency to lie in a specific band. With more specialized antennas or receiver designs, designers can tune the antenna to operate in multiple bands. Although dual-band antennas are available on the market, they easily exceed the costs of a 3D-printed circuit board and do not offer tunability to every frequency band.

RF circuit designers must consider the power received/transmitted, as well as the bandwidth of their device when optimizing their design and choosing an appropriate substrate material. The transmission line geometry—i.e., microstrip, stripline, or grounded coplanar waveguide—also influences the expected performance.

3D printing RF components directly onto a 3D-printed PCB offers designers the ability to tune the operating frequency to nearly any band within the limits of available materials. The impedance of the radiating/receiving conductor will depend on the trace geometry and substrate properties. Using an additive manufacturing system allows designers to quickly experiment with many different trace geometries, ground plane designs and other design techniques with the goal of optimizing return/insertion loss and radiated power in the desired frequency band.

With antennas, as the RF carrier frequency increases, the thickness required for a highly sensitive antenna decreases and can eventually reach the resolution limit for the printer. The electromagnetic field can only penetrate a few skin depths into the conductor, thus the effective thickness of a printed conductor should not significantly exceed the skin depth (e.g., 2 μm of silver at 10 GHz).

When selecting an additive manufacturing system for RF components, you’ll need to take the printer’s vertical resolution limits and the conductivity of your printed conductors into account to maximize the sensitivity of your component. Compared to fused deposition molding, where the printing resolution is limited by the nozzle aperture, inkjet 3D printers that use nanoparticle conductive inks provide superior resolution, in the order of a few microns. This makes inkjet printing ideal for printing conductors for high-frequency, high-performance RF components.

3D-printed WiFi receiver and transmitter

A 3D-printed receiver and transmitter for WiFi communication.

Finally, 3D printing allows fabrication of RF components on PCBs with a unique footprint or even non-planar geometry. This allows the shape of a component to be adapted to the shape of its enclosure, rather than being constrained by packaging compromises. Lamination and cutting procedures that are normally used with traditional PCB manufacturing processes are not needed, which decreases product development time and ultimately time to market.

Can My Company Benefit from 3D Printing RF Components?

Any cutting-edge electronics company or research institution can benefit from 3D printing RF circuits. Larger companies working on NPI and research institutions can quickly fabricate and validate new prototypes without sending them to an external manufacturer. The reduced cost and reduced risks of rapid in-house prototyping enabled by additive manufacturing will inspire companies to experiment and develop new innovative products. Companies in highly regulated industries like defense and aerospace can also benefit, especially when building low-volume systems. These companies can fabricate unique RF amplifiers, transceivers, antenna arrays, and other devices without IP security risks.

3D printing RF components can save you a significant amount of time and money, as well as giving you complete control over your design. The award-winning DragonFly Pro system is the only precision additive manufacturing system built specifically for in-house rapid prototyping and production of planar and non-planar electronics, including RF components. Read a case study or contact us today to learn more about DragonFly Pro.

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