Abstract
In high frequency circuit boards PTFE is widely used as a
substrate material. It offers very low dielectric
constant and low losses. However, it is relatively
expensive to fabricate, making the cost of PTFE laminates
high. In addition PTFE-based circuit boards are composite
materials with glass fiber reinforcement and thus not
isotropic. Glass fiber also increases losses compared to
raw PTFE. We have developed a new proprietary
thermoplastic substrate especially for high frequency
circuit boards. This polyphenylene ether (PPE) based
substrate offers a low dielectric constant (dk), 2.55,
and low dielectric loss (df), 0.002, in 1 to 5.5 GHz
frequency range. It is unfilled, which makes the
properties both isotropic and completely homogeneous
throughout the substrate. This new material can be
processed by typical thermoplastics processing methods,
such as film and sheet extrusion and injection molding.
Among thermoplastics, PPE is inherently low burning
material and it can be easily made flame retardant (V0).
However, the addition of flame retardant was found to
slightly increase the dielectric loss at high
frequencies. This plastic material exhibits a high glass
transition temperature, Tg, around 200°C. This also gives
the highest short term use temperature. There is no
crosslinked structure to support the substrate above Tg.
Processes requiring higher temperatures, such as
conventional lead free reflow soldering or wave soldering
can not be used. Because of the very good dielectric
properties the material is intended for high frequency
applications where the number of required solder
connections is limited. One of these is a broadband base
station antenna. The performance of this new material as
a UMTS/WCDMA antenna for 1.92 - 2.17 GHz frequency band
was evaluated with very promising results. First, a patch
antenna was designed based on simulations and then the
demo antenna was built. The measured performance
coincided well with the simulation data. Design of a full
size base station array antenna demonstrator is also
presented
Original language | English |
---|---|
Title of host publication | Proceedings |
Subtitle of host publication | IPC APEX EXPO Technical Conference 2011 |
Publisher | Curran Associates Inc. |
Pages | 2895-2920 |
Volume | 4 |
ISBN (Print) | 978-1-6178-2845-4 |
Publication status | Published - 2011 |
MoE publication type | A4 Article in a conference publication |
Event | IPC APEX EXPO Technical Conference 2011 - Las Vegas, Nevada, United States Duration: 12 Apr 2011 → 14 Apr 2011 |
Conference
Conference | IPC APEX EXPO Technical Conference 2011 |
---|---|
Country/Territory | United States |
City | Las Vegas, Nevada |
Period | 12/04/11 → 14/04/11 |