Arlon AD450 PCB laminate: full dielectric properties, datasheet specs, Dk 4.5 performance, and real-world RF/microwave applications explained by engineers, for engineers.
If you’ve spent any time specifying materials for RF or microwave PCB designs, you’ve probably hit the same wall most engineers hit: FR-4 works fine up to a point, and then it simply doesn’t. The signal gets sloppy, insertion loss climbs, and your antenna patterns stop matching simulation. That’s usually when the search for a better substrate begins โ and Arlon AD450 is one of the materials that comes up early in that conversation.
This article walks through what AD450 actually is, what its datasheet numbers mean in practice, how it compares to alternatives, and when it genuinely makes sense to specify it over other options.
What Is Arlon AD450?
Arlon AD450 is a woven fiberglass reinforced, ceramic-filled, PTFE-based composite laminate designed for use as a printed circuit board substrate in microwave and RF applications. It belongs to Arlon’s AD (Advanced Dielectric) series, a family of cost-optimized PTFE and ceramic composite materials aimed at commercial wireless, antenna, and broadband applications.
The “450” in the product name corresponds to its nominal dielectric constant of 4.5 โ a deliberate design decision that makes it a near drop-in replacement for FR-4 from an impedance and trace geometry standpoint. Most FR-4 designs hover around a Dk of 4.2โ4.8 depending on glass style, frequency, and manufacturing variability. AD450 hits 4.5 with far tighter consistency and much better high-frequency performance.
Originally, Arlon offered AR450, which used non-woven fiberglass reinforcement. AD450 was developed as its successor, with the switch to woven fiberglass delivering better Dk uniformity across a panel, improved dimensional stability, and reduced manufacturing costs. If you’re quoting fabrication on a design originally specified for AR450, AD450 is the direct replacement Arlon recommends.
It’s worth noting that following Rogers Corporation’s acquisition of Arlon’s electronic materials division, AD450 is now sometimes referenced as a Rogers product. The datasheet and material specs remain the same.
Arlon AD450 Key Dielectric Properties
This is where most engineers need to spend time before committing to a design. The table below summarizes the critical electrical and physical properties of Arlon AD450 based on its published datasheet.
Electrical Properties
| Property | Value | Test Method |
| Dielectric Constant (Dk) | 4.5 (nominal) | IPC TM-650 2.5.5.6 |
| Dissipation Factor (Df) | ~0.002 (at 10 GHz) | IPC TM-650 2.5.5.6 |
| Dk Stability vs. Frequency | Excellent โ flat across frequency | โ |
| Df Stability vs. Frequency | Excellent โ stable across frequency | โ |
| Volume Resistivity | High | IPC TM-650 2.5.17.1 |
| Surface Resistivity | High | IPC TM-650 2.5.17.1 |
The Dk of 4.5 is notably stable across a wide frequency range โ from low microwave through the higher GHz bands. This is one of the most important differences from FR-4, whose Dk can shift by 0.3โ0.5 across frequency, creating impedance drift in broadband designs. For any design where signal fidelity across a wide bandwidth matters โ wideband antennas, multimedia transmission systems, multi-band transceivers โ that stability directly affects your return loss and insertion loss budget.
The dissipation factor is where PTFE-based materials like AD450 really separate themselves from standard epoxy laminates. FR-4 Df typically runs 0.02โ0.025 at microwave frequencies. AD450’s Df in the 0.002 range is roughly a 10ร improvement. Over a few inches of trace at 5โ10 GHz, that translates to measurable signal preservation.
Thermal and Mechanical Properties
| Property | Value |
| Thermal Conductivity | Higher than standard PTFE laminates |
| Z-axis CTE | Low (improved vs. standard PTFE) |
| X-Y CTE | Stable, woven glass controlled |
| Copper Peel Strength | Superior PTH adhesion |
| Panel Size | Large panel format available (36″ ร 48″ master sheet) |
The ceramic filler in AD450 serves a dual purpose. First, it raises the Dk to 4.5 โ pure PTFE without filler lands around 2.1, far too low to be useful as a direct FR-4 replacement. Second, it improves thermal conductivity relative to unfilled PTFE, which is naturally a poor thermal conductor. That matters in power amplifier boards and other high-dissipation applications where heat buildup degrades PTFE performance over time.
The low Z-axis CTE is particularly valuable for plated through-hole (PTH) reliability. Standard PTFE laminates expand significantly in the Z-axis under thermal cycling, which creates stress on barrel-plated holes and can lead to fatigue failures. The ceramic loading in AD450 pulls Z-axis CTE down, bringing it closer to the behavior of conventional epoxy laminates and improving PTH reliability substantially.
Standard Thickness Availability
| Thickness (inches) | Thickness (mm) |
| 0.010″ | 0.254 |
| 0.020″ | 0.508 |
| 0.030″ | 0.762 |
| 0.040″ | 1.016 |
| 0.050″ | 1.270 |
| 0.060″ | 1.524 |
| 0.070″ | 1.778 |
Available with standard 1 oz and 2 oz rolled copper foil. Immersion gold (ENIG) finish is commonly specified for antenna and RF applications where solderability and surface oxidation are concerns. The large master sheet size (36″ ร 48″) makes it practical to run multiple boards per panel, which helps manage per-unit cost on production runs.
AD450 vs. AR450: Understanding the Upgrade
Engineers who’ve been in this space for a while will remember the AR450 โ Arlon’s earlier non-woven fiberglass / PTFE / ceramic composite with essentially the same target Dk. The switch from non-woven to woven fiberglass reinforcement in AD450 brought three practical improvements:
Better Dk uniformity across a panel. Non-woven glass fiber distribution is inherently less consistent than woven glass. Woven styles give you more predictable Dk from point to point, which directly improves impedance control tolerance across a production panel.
Better dimensional stability. Woven glass constrains X-Y movement more uniformly. For fine-feature microwave circuitry where trace width tolerances are tight, better dimensional stability reduces registration errors in etching and drilling.
Reduced manufacturing cost. Woven glass styles used in AD450 are more widely available and easier to process than some non-woven alternatives. This makes the material more accessible for volume production without a cost penalty.
The electrical performance remains comparable to AR450, so legacy designs specified on AR450 should translate directly with no required trace geometry changes.
Arlon AD450 Applications
Wideband Antenna Designs
This is probably the most common home for AD450 in the field. Wideband and multi-band antennas โ including patch arrays, slot antennas, and monopoles operating from UHF through low microwave โ benefit enormously from a substrate with stable Dk across frequency. When Dk shifts with frequency, your resonant structures shift with it, degrading gain and matching bandwidth. AD450’s flat Dk response allows antenna designers to simulate accurately and build to spec.
FR-4 Replacement in Higher Frequency Applications
One of the explicit design goals for AD450 was to make FR-4 replacement as painless as possible. With Dk = 4.5, trace widths calculated for FR-4 transfer with minimal adjustment. This makes AD450 attractive for product upgrades where a design originally built on FR-4 has outgrown its frequency ceiling โ whether due to a new frequency band requirement, tighter signal integrity spec, or reliability concerns at elevated temperatures.
A common scenario: a WiFi or LTE module board designed for 2.4 GHz on FR-4 needs to be extended to cover 5.8 GHz or new 6 GHz bands. Redesigning for AD450 gives you meaningful margin in Df and Dk stability without redesigning your entire trace geometry.
Multimedia Transmission Systems
Broadband signal transmission for multimedia โ think set-top box RF front ends, point-to-point wireless links, and cable headend equipment โ places a premium on consistent signal fidelity across a wide channel. AD450’s combination of low Df and stable Dk makes it a reliable substrate for these systems.
Circuit Board Miniaturization
Higher Dk materials allow physically shorter transmission line structures for a given electrical length. At Dk = 4.5, AD450 permits meaningful miniaturization compared to lower-Dk PTFE substrates while still outperforming FR-4 in signal quality. For embedded RF front-ends where board area is at a premium, this combination of density and performance is practical.
High-Power RF Designs
The ceramic loading that lifts AD450’s Dk also improves its thermal conductivity compared to unfilled PTFE. Combined with low Z-axis CTE, this makes it usable in power amplifier boards and combiner networks where heat dissipation and dimensional stability under thermal cycling both matter. Applications here include base station power amplifiers, radar transmit modules, and industrial RF generators.
Arlon AD450 vs. Competing Materials
Choosing a laminate is never just about one material’s spec sheet โ it’s about fit for your specific application, process compatibility, and cost envelope. Here’s how AD450 sits relative to common alternatives.
AD450 vs. FR-4
| Parameter | FR-4 | Arlon AD450 |
| Dielectric Constant (Dk) | ~4.2โ4.8 (variable) | 4.5 (stable) |
| Dissipation Factor (Df) | 0.020โ0.025 | ~0.002 |
| Dk vs. Frequency | Drifts noticeably | Very stable |
| Thermal Conductivity | ~0.3 W/mยทK | Higher |
| Z-axis CTE | High | Low (ceramic loaded) |
| Cost | Low | Moderate to high |
| Processability | Standard | PTFE-compatible process |
FR-4 remains the right answer for the vast majority of digital and low-frequency analog designs. But once you’re running signals above 1โ2 GHz with any meaningful path length, the gap in dissipation factor starts showing up as measurable insertion loss and pattern distortion. AD450 is the sensible step up when FR-4 performance runs out.
AD450 vs. Rogers RO4003C
| Parameter | Rogers RO4003C | Arlon AD450 |
| Dielectric Constant (Dk) | 3.55 | 4.5 |
| Dissipation Factor (Df) | 0.0027 at 10 GHz | ~0.002 |
| Base Material | Ceramic-filled thermoset | Ceramic-filled PTFE |
| FR-4 Processability | Yes (thermoset) | Requires PTFE process |
| CTE | Low | Low |
| Typical Use | General RF/microwave | FR-4 replacement, antennas |
RO4003C is a ceramic-filled hydrocarbon thermoset rather than PTFE โ it processes much like FR-4, which simplifies fabrication. If your fab house doesn’t have strong PTFE processing capability, RO4003C may be easier to execute reliably. For designs where Dk = 4.5 is specifically needed for FR-4 geometry compatibility, AD450 is the better match.
AD450 vs. Arlon AD600
AD600 offers a higher dielectric constant (Dk ~6.0) and is aimed at applications requiring more aggressive miniaturization โ ultrathin antenna substrates and multilayer circuits where physical size is the primary constraint. If you need smaller structures and can tolerate the trace width recalculation that comes with a higher Dk material, AD600 is worth evaluating. AD450 is the better general-purpose FR-4 replacement.
Processing and Fabrication Notes for Arlon AD450
AD450 is processed using standard PTFE-based PCB substrate methods. If you’ve built boards on Arlon DiClad, CuClad, or IsoClad series materials, the process is familiar. A few points worth flagging for engineers working with fabricators who primarily run FR-4:
PTFE prep requirements. PTFE-based materials need sodium etching or plasma treatment before plating to achieve adequate adhesion. Standard FR-4 adhesion promotion chemistries won’t work. Confirm your fabricator has this capability before quoting.
Drilling. PTFE is soft and somewhat springy compared to FR-4. Entry and exit materials, drill geometry, and feed rates need to be dialed in for clean hole quality. Most fabricators with microwave laminate experience handle this routinely.
Dimensional stability. AD450’s woven glass construction gives it better dimensional stability than non-woven PTFE laminates, but it still won’t match FR-4’s rigidity for large-format boards. For boards larger than 8โ10 inches in either dimension, confirm your design can tolerate the somewhat lower rigidity.
PTH reliability. The ceramic loading and low Z-axis CTE of AD450 improve PTH reliability significantly compared to unfilled PTFE laminates. This is one of the specific engineering improvements AD450 makes over traditional PTFE materials.
Arlon publishes fabrication guidelines specifically for DiClad, CuClad, IsoClad, and AD Series laminates โ these are worth downloading and sharing with your fabricator before kickoff.
For engineers looking to build on Arlon PCB materials including AD450, working with a fabricator who has established PTFE processing capability is the single biggest factor in getting consistent results.
Datasheet and Specification Resources
Finding current Arlon datasheet information can be slightly confusing now that Rogers acquired Arlon’s electronic materials division. Here are the most reliable places to find spec data:
| Resource | What You’ll Find |
| Rogers Corporation AD450 Product Page | Current datasheet, specs, ordering info |
| Arlon RF & Microwave Materials Guide (PDF) | AD series comparison table, thickness availability |
| Arlon AD Series PDF via Cirexx | Dk vs. frequency curves, Df vs. frequency curves |
| RF Global Net โ AD450 Laminate Page | Fabrication guide download link, application notes |
| IPC TM-650 Test Methods | Reference for how Dk and Df values are measured |
The Dk vs. frequency and Df vs. frequency curves in the AD Series datasheet are particularly useful during the material selection phase โ they let you validate performance at your specific operating frequency rather than relying on a single-point spec value.
AD450 Design Considerations: A Few Things Engineers Miss
Dk tolerance matters more than the nominal value. When designing transmission lines, patch antennas, or filters, the tolerance on Dk directly affects your impedance tolerance. AD450 offers tighter Dk control than typical non-woven PTFE laminates โ use this in your impedance budget calculation rather than just the nominal 4.5 value.
Dissipation factor at operating frequency. The datasheet Df value is typically reported at 10 GHz. If your operating frequency is significantly different, check the Df vs. frequency curve. PTFE-based materials are generally well-behaved across frequency, but confirming this for your specific band is good practice.
Thermal management in power applications. AD450’s improved thermal conductivity relative to unfilled PTFE is a genuine benefit, but if you’re running significant RF power (tens of watts or more), plan your thermal vias and heatsinking accordingly. Improved doesn’t mean unlimited.
Copper foil surface roughness. At higher microwave frequencies, conductor loss from surface roughness becomes significant. AD450 is typically available with standard microwave-grade copper foil. If you’re operating above 10โ15 GHz and insertion loss is critical, discuss low-profile copper options with your fabricator.
Frequently Asked Questions About Arlon AD450
Q1: Can I use my existing FR-4 PCB design files directly with AD450 without redesigning trace widths?
In most cases, yes. With a Dk of 4.5, AD450 closely matches the dielectric constant of typical FR-4. Most transmission line structures and impedance-controlled traces will not require significant width adjustment. You should verify impedance with your fabricator’s specific stackup and confirm using a field solver, but the geometry change required is typically small โ a practical advantage that was specifically engineered into AD450.
Q2: What frequencies is Arlon AD450 suitable for?
AD450 is suitable from low microwave through several GHz. Its stable Dk and low Df make it appropriate for applications in the UHF band through approximately 10 GHz and beyond for many circuit types. Exact upper frequency utility depends on your acceptable insertion loss budget and circuit geometry. For applications operating above 20โ30 GHz, lower-Dk, lower-loss PTFE laminates may offer better performance.
Q3: How does AD450 compare to the older Arlon AR450?
AR450 used non-woven fiberglass reinforcement; AD450 uses woven fiberglass. The electrical performance targets are essentially the same (both aim for Dk ~4.5), but AD450 delivers better Dk uniformity across a panel, better dimensional stability, and lower manufacturing cost. Arlon designed AD450 specifically as AR450’s replacement, and the materials are considered functionally equivalent for most design purposes.
Q4: Is Arlon AD450 still available now that Rogers acquired Arlon?
Yes. Rogers Corporation completed its acquisition of Arlon’s electronic materials division, and AD450 remains part of the product portfolio. It may be listed under Rogers’ branding in some supplier catalogs. Lead times and availability can vary, so checking with your PCB fabricator or a Rogers-authorized distributor before final design lockdown is advisable.
Q5: What surface finishes work well with Arlon AD450?
ENIG (Electroless Nickel Immersion Gold) is the most commonly specified finish for AD450 in antenna and RF applications โ it provides excellent coplanarity and consistent solderability without the oxidation issues of bare copper or HASL. OSP (Organic Solderability Preservative) is used in some commercial applications. For connectors and edge-launch applications, confirm finish compatibility with your connector supplier.
Summary
Arlon AD450 occupies a genuinely useful position in the laminate landscape: it delivers PTFE-based RF performance โ stable Dk, low dissipation factor, good thermal behavior โ at a dielectric constant specifically engineered to make FR-4 migration practical. For engineers dealing with designs that have outgrown FR-4’s frequency ceiling but where a Dk of 2.5 or 3.5 would require a full trace-geometry redesign, AD450’s 4.5 Dk is a practical path forward.
The ceramic filler adds thermal conductivity and reduces Z-axis CTE, making it a more reliable PTH substrate than standard PTFE laminates. The move to woven fiberglass reinforcement over the older AR450 tightened Dk uniformity and dimensional stability across a panel. Both are meaningful engineering improvements, not marketing language.
Whether you’re designing a wideband base station antenna, a multimedia system front-end, or upgrading a legacy FR-4 RF board to handle a new frequency band, AD450 is worth evaluating seriously as part of your material selection process.
Typical properties listed in this article are based on published Arlon datasheet information and should not be used as specification limits. Contact your Arlon/Rogers representative or authorized distributor for current specification data and fabrication guidance specific to your application.
