order to design a product with the advantages of low loss tangent and suitability for sequential lamination. Among the polymers, polytetrafluoroethylene (PTFE) is the most preferred host matrix that exhibits excellent dielectric properties such as low permittivity (ε r = 2. 6 Tribology/Slip and. RO3010 laminates are competitively priced products with exceptional mechanical and electrical stability. 60, tanδ = 0. The dielectric loss angle tangent (tan δ) of the PTFE composite also showed an increasing trend with the filler content. 5 GHz show that the 3D printed PTFE maintains the favorable dielectric properties of traditionally processed PTFE. It has a dielectric constant of 2. In the design of the. Tapes, sheets and finished products can be supplied etched. 0 in the z-axis at 10 GHz tightly. Where tan δ is the dielectric loss factor of the substrate and f is frequency. 55 Nd 0. To achieve polytetrafluoroethylene (PTFE)-based composites for high-frequency applications with low dielectric constant, low dielectric loss tangent and low coefficient of thermal expansion (CTE), a novel pentafluorostyrene (PFS) interface modifier was used to achieve excellent performance for SiO 2 /PTFE composite materials. 2. As shown in Fig. 0% BN/PTFE composits in ablation process is 21. The difference between SFR and PTFE includes scattering loss and dielectric loss. Decomposition Temperature (Td) by TGA @ 5% weight loss: Resin Content: 360: Df, Loss Tangent: Resin Content: 0. ), and a. It was reported that <0. The only way you can reduce it is to use a dielectric with a very low loss tangent, or low dielectric constant. The loss tangent of Borofloat 33 glass increases from 0. In loss tangent AFM, the AFM cantilever is excited, similar to amplitude modulation AFM (also known as tapping mode); however, the observable aspects are used to extract dissipative and conservative energies per cycle of oscillation. 02 in this frequency range. It is a measure of the amount of energy loss from the material due to an external electric field. Fig. 011: GOOD Dielectric Constant 4. The loss tangent of SU-8 is also given in Fig. Loss tangent values ranging from . At 80% relative air humidity, chemically modified jute fabrics have 38–179% and 1. = 진공의 유전율 은 진공 상태에서 / 값으로, 다음과 같이. Loss tangent presuming only ohmic (conduction) loss is given by Equation 3. LaminateR-5785(N)/Prepreg R-5680(N) The ultra-low dielectric constant (Dk) and dissipation factor (Df) make MEGTRON 7 ideal for high speed and large data volumes associated with servers and routers required for 5G. 1 Understanding Dielectric Constant and Loss tangent on Radome and Antenna DesignIn addition, I-Tera MT40 offers a lower dissipation factor (Df) of 0. Where relevant, this includes physical properties, thermal properties, B-H curves, core loss data, frequency dependent permittivity and frequency-dependent loss tangent – enabling more exact analysis for key classes of electromagnetic simulation. 1 Mechanical properties 34 3. 05 (CW) to 2. In the present work, fillers having different temperature coefficient of permittivity ( τ ε r ) were incorporated in the PTFE matrix near to the optimum filler loading, and we studied the effect. 11 at 3. field and is highly frequency dependent. Chemical structure of PTFE. 1 at 10 GHz (Fig. Toray's electrically pure, low-loss materials and syntactics ensure maximum radome efficiency. Polymeric thin films have low loss tangent values, therefore contributing less dielectric loss at high frequencies. 2 Radome Design Elements. 2E-4 @100 MHz. 25 vf micro Sm2Si2O7 composites showed a relative permittivity and dielectric loss of 3. This isn't much, but it is about 1/4% drop in power for every wavelength, which isn't. 2) E 1080 B RC SC Reinforcement Type (see 1. For typical amplitude sweeps, an angular frequency of ω = 10 rad/s is generally used. The microwave dielectric properties of ZrTi2O6/PTFE composites were measured using stripline resonator method. Dielectric loss tangent or dissipation factor. 5 and above Loss Tangent 0. For example, the dielectric constant and loss tangent of 30 vol% hybrid fillers/PTFE composites are 3. 004–0. The relative dielectric constant (ε r) and loss tangent (tanδ) of the composites. 045 (2. Rutile filled PTFE composites have been fabricated through Sigma Mixing, Extrusion, Calendering and Hot pressing (SMECH) process. 4. Polytetrafluoroethylene (PTFE) polymer is an example of a linear fluoropolymer. But it also has certain disadvantages like high coefficient of thermal expansion (∼109 ppm/°C) and inferior dimensional stability [4] , [5] . 6” • PTFE (Teflon) 25dB loss is 22. and it influences cost of devices. 17. 10 , both untreated BZT/GF and F8261 modified BZT/GF filled PTFE composites exhibited a relatively low values of dielectric loss. The laminates are PTFE-based materials produced by [49,50]. 8" L=8. 5 ¥ 10-3 at 60 GHz which exhibits significant impact on total loss in mm-Wave device but the processing for PTFE is also known to be difficult. 1: Z-Axis CTE: 50 to 260°C, (Total Expansion) 2. However, the main disadvantage of PTFE is the negative temperature coefficient of dielectric constant (τ ε ∼-400 ppm/°C) making it difficult to be used in microwave circuit devices. The composites were prepared through a dry powder processing technique by dispersing different micron sizes (25 µm, 45 µm, 63 µm, 90 µm, and 106 µm) of the recycled BRS filler in the PTFE matrix. Polyimide (PI)/ bisphenol A dicyanate esters (BADCy) composite laminates with varying resin contents were prepared by filament winding and autoclave molding process. The data in Chart 2 shows the distribution of dissipation factor for RO3003 and RO3035 materials. Comparing the two kinds of results of the PTFE sample shown in figure 4(A), we see that the biggest difference of the dielectric constant is 0. (FR-4) processes. Eccostock LoK is a low dielectric constant, low loss and low weight thermosetting plastic for RF and microwave insulation. Dielectric materials cannot resist indefinite amount of voltage and with enough voltage applied, any insulating material. The formula to calculate the dissipation factor of an insulator is as follows: Where: DF is the dissipation factor or loss tangent; δ is the phase angle between the voltage and current waveforms in the insulator; I R is the resistive current; I C is the. 1), extremely low loss tangent (tg δ = 10 −4 at 1 GHz), corrosion resistance, excellent chemical resistance, and is stable in a wide range of frequencies [8], which make it a. 0010 0. 2 Radome Design Elements. RT Duroid 5870 substrate has low loss tangent. The conductivity of PTFE/CNT (5 wt%) nanofiber membranes reached 1. Example 6-layer stackup with a PTFE laminate on the outer layer and FR4 laminates on inner/bottom layers. Temperature Operating Range -55 to +200 deg C. 6 (a). ECCOSTOCK HIK500F is a low loss stock with adjusted dielectric constants up to 30 and over 200°c temperature resistance. 25 Of particular concern in many low-temperature measurements is the dc resistance and rf loss, which can create ohmic heating and degradation of quantum information. 1. Rogers RO4350B materials are proprietary woven glass reinforced hydrocarbon/ceramics with electrical performance close to PTFE/woven glass and the manufacturability of epoxy/ glass. 4 a–b. 8. 4 (a) closely follows the profile of in Fig. 4. 5 × 10⁻³ at microwave frequencies (around 10 GHz). 2 Properties under long-term stress 36 3. 1 and a loss tangent<0. Low dielectric loss and low-cost recycled borosilicate (BRS) glass-reinforced polytetrafluoroethylene (PTFE) composites were fabricated for microwave substrate applications. Membr. 2-2. The values from the associated chart are obtained by the analysis of both the moulding and extrusion process. Published in: 2006 International Conference on Microwaves, Radar & Wireless CommunicationsFigure 6. Figure 7 shows the variation of moisture absorption of PTFE/SiO 2 composites with the mass ratio of small size particle. Silicon dioxide-filled semi-rigid coax cables can withstand temperatures that would cause PTFE-filled cables to catch on fire! S No Material Dielectric constant Loss Tangent 1 Unreinforced PTFE, Cuflon 2. 0022 (10 GHz) at an optimum filler volume fraction of 46% ZrTi2O6. material. The first column on the left sums-up the basic data of virgin PTFE G400, in order to compare with the values of the. It is a measure of the amount of energy loss from the material due to an external electric field. 73 and low dielectric loss of 3. 011 and above: Laminate Impact Strength: Very. C. with PTFE glass materials. Also the −10 dB bandwidth narrows, as the return loss gets worse with the increasing relative permittivity. 0031 making it a cost effective alternative to PTFE and other commercial microwave and high-speed digital laminate materials. 2. Dielectric loss angle tangent is increasing as increment of. The decrement in filler size from 106 μm to 25 μm also increased the mean dielectric constant and loss tangent of the composites from 2. PTFE. 0; C. 4 Properties under cyclic stress 43 3. Resonac believes these properties are greatly affected by the difference in scattering loss. Excellent mechanical properties versus. 5 %, Donghai Powder Technology Co. The CuClad 6250 bonding film is available in both 24” (610mm) roll form and sheeted format. Loss tangent values ranging from . 5Hello everybody, I have the refractive index values of a new material over wavelength. 031 at 0. 2. 25) and dielectric loss (tanδ of 0. 5. It is the ratio of the magnetic induction to the magnetizing field as a function of the field in a material. The ε of the PTFE composite film (PTFE/BN/m-AlN) with 90 wt% filler content was only 3. 0018 at X-band and low moisture absorption. When the frequency was above 1 MHz, the loss tangent of all the PTFE composite samples was lower than 0. 6 Thermal stability of AlN/PTFE composites. k. Permittivity and loss tangent of the composite substrates were measured at X-band frequency region (8. 7–5. 1 and dissipation factor tgδ < 0. 0031 — Bereskin Stripline Volume Resistivity: C-96/35/90 1. 02 and a loss tangent of 0. The dielectric loss increases with increasing values of Df. Unlike PTFE based microwave materials, no special through-hole treatments or handling procedures are required. 08E ⁻⁴ ), higher bending strength (21. 0018 while. The result is much lower loss at microwave frequencies than solid PTFE offers. PTFE also has a very low loss tangent with a typical value of tan δ = 4 × 10 −4 , which decreases by a factor of 2-3 from 300 K down to 4 K [51, 52]. Meanwhile, the dielectric constant and dielectric loss of PTFE/CNT (5 wt%) nanofiber membranes are 58. 2. Loss tangent versus temperature at 1. The fused amorphous SiO 2 has a dielectric constant of approximately 3. 2. For the extraction of dielectric constant and loss tangent of the proposed stack up, microstrip ring resonator (MRR) method is used. Dielectric constant: Although this is sometimes misunderstood, and everyone tends to just go for low-Dk laminates, but high-Dk. 5. measure the microwave dielectric loss tangent of a variety of materials. 021 (assumed constant) • Skin Loss = Dielectric Loss at f e = 205 MHz Typical Values for FR-4 & Common Line Parameters. Wide dielectric constant range available: 2. Spacing between the radar antennas and the radome:PTFE-based ceramic-polymer dielectric composites have been widely researched in the communication field due to their good processing, wide range frequency and temperature stability and being able to provide tunable dielectric constant in a scale. PTFE 2. In loss tangent AFM, the AFM cantilever is excited, similar to amplitude modulation AFM (also known as tapping mode); however, the observable aspects are used to extract dissipative and conservative energies per cycle of oscillation. RT/duroid 5880 laminates has a low dielectric constant (Dk) and low dielectric loss, making them well suited for high frequency/broadband applications. For the simultaneous analysis of both thermal conductivity and dielectric properties according to the PTFE content, the in-plane and through-plane thermal conductivity, permittivity, and. RO3000® Series. 5%E shows a slight increase with. Rogers CLTE-XT laminates are composites of micro-dispersed ceramic filler, PTFE and woven fiberglass reinforcement, designed to improve loss tangent while maintaining good dimensional stability. 8°,. Polytetraflouroethelene, a long-chain molecule, one form of it is registered under the Dupont trademark "Teflon". The loss tangent for ptfe is about 0. 255 at 1. 6648. , the patch is treated as a wide piece of a microstrip line. Using eqn 3, plugging in the speed of light. Dyneon™ PTFE continues to meet tough demands for new applications and maintains proven success and high reliability in the following industries: Automotive PTFE and PTFE compounds are. When the resin. moulding medium viscosity acetal resin for injection moulding. VICTRE X 450G™ Polymer Injection Notes Runner : Die / nozzle >3mm, manifold >3. The ZrTi2O6/PTFE composites exhibit a dielectric constant of 7. 0005 0. 00155 whereas for nano Sm2Si2O7 composites with same volume fraction the values. The high was the main cause of the lower values of , which explains the unexpectedly. 4 THz. 37 shows an idealized radome. It is possible to create low-cost RF circuit cards on FR-4, but the losses will always be much higher than on PTFE-based boards from reputable suppliers. Polyetheretherketone is ahigh performance thermoplastic that is strong, stiff, hard and has high temperature resistance. Thus, loss tangent provides an alternative way to quantify the effect of loss on the electromagnetic field within a material. 3. Mechanically,. 2, 0. 05±0. Environmental Specifications. These products were developed to provide unique material solutions for current and emerging RF/Microwave design and automotive radar requirements. The relative dielectric constant (ε r) and loss tangent (tanδ) of the composites increase with an increase of the volume fraction of ZrTi2O6. The composites were prepared through a dry powder processing technique by dispersing different micron sizes (25 µm, 45 µm, 63 µm, 90 µm, and 106 µm) of the. Step 3: Select the correct membrane area to. PTFE-based composites are widely used for the fabrication of microwave circuit boards [3], [4]. 9. 5 and above Loss Tangent 0. PTFE loss tangent was set to zero, as the realistic loss tangent of PTFE is extremely small anyway, and the shortness of the line further reduces any significant losses in the coaxial line. Exceptional product support and product quality. 16556-16560. Radar and satcom signal clarity is a complex function of design and material. 6 Hz. 1. PTFE has low dielectric constant ε ′ r ∼ 2. School of Materials Science and Engineering, State Key Lab Silicon Mat, Zhejiang University, Hangzhou, 310027 People's Republic of China. Loss tangent, storage modulus and loss modulus of various polymers. Relative permittivity is the factor by which the electric field between the charges is decreased relative to vacuum. Phase formation was confirmed by powder X-ray diffraction studies. Polytetrafluoroethylene (PTFE) is a totally fluorinated polymer which is white, semi-opaque, and semi-crystalline. Loss tangent: This is the first major area that PCB designers will use to start comparing material options. First Shield Silver Plated Copper Braid . 0002. The PTFE/PVDF coating (containing 20 wt% of PTFE) exhibits synergistic effect with high water contact angle (CA, 153. 8 × 10 −4, at 15 K. Materials with a low loss tangent and low relative permittivity are essential for the next. 1 and extremely low loss tangent tan δ ∼ 0. 33 x 107 MΩ-cm 2. This family of advanced laminates offers exceptional electrical and mechanical stability. Loss Tangent and Dielectric Relaxation Time - I ( ) c n k eff ω =ω ωε σ ε ε n ω j o eff = 1− The complex wavevector is: The complex refractive index is: Loss tangent Loss tangent = ωε σ But the dielectric relaxation time was: σ ε τd = ⇒ Loss tangent = ωτd 1 And: o d neff j ε ωτ ε ω 1 = 1− Loss tangent ECE 303 – Fall. 011: GOOD Dielectric Constant 4. Where data were available, the loss tangent for PTFE (Teflon) reported were all close to zero (at least as small as about 10 −3), same as those we obtained here. Loss tangent: '' tan C ' es d e we == (6. The ε of the PTFE composite film (PTFE/BN/m-AlN) with 90 wt% filler content was only 3. 018;. The result is a low loss material which can be fabricated using standard epoxy/glass (FR-4) processes offered at competitive prices. Because of the high loss tangent, don't try to make any filter structures! Properties of FR-4. An intermediate layer is often. Stretching is more important at lower frequencies and data rates, which affects the trace. 2. 0010 to 2. 18 and 0. Rogers offers a wide variety of materials used for high-frequency PCBs with a relative permittivity ranging from 2. 0035 at 100 Hz. Yu, T. 2. Copolymers of tetrafluoroethylene and hexafluoropropylene showed two dielectric loss peaks: one. SFR can be applied to low-roughness copper foil, whereas PTFE can only. Second Shield Silver Plated Copper Braid 0. 5. If particle size is kept small compared to a wavelength, and the ratio of materials is well maintained from batch to batch, the mixture will be well behaved. Low-loss, high frequency advanced materials with well-controlled dielectric properties to enable microwave and RF applications, including mobile networks. Solid PTFE has a dielectric constant of 2. Features. , their dielectric constants are not dependent of the frequency as electronic polarization is instantaneous regardless of frequency. 038mm)Rogers DiClad 527 laminates are woven fiberglass reinforced, PTFE-based composite materials for use as printed circuit board substrates. Lower Z-Direction CTE than traditional PTFE woven-glass laminates. Loss Tangent (RC64%) 10 GHz (SPC method) 0. Prepreg. Because the large-scale relaxations of the PBT melting were. 7 Loss tangent: 0. PTFE loss tangent was set to zero, as the realistic loss tangent of PTFE is extremely small anyway, and the shortness of the line further reduces any significant losses in the coaxial line. The conductivity of PTFE/CNT (5 wt%) nanofiber membranes reached 1. 5. The coefficient of sliding friction between PTFE and many engineering materials is extremely low and when sintered with wear reducing compounds, an industrially important class of bearing materials are formed. 5Gbps Interconnects Slide 6 High Performance Engineering & DesignCa 0. 6. 0015 0. View Article. Substrate materials like FR-4 (epoxy resin), PTFE (Polytetrafluoroethylene), Ceramic, and metal core (copper or aluminum) are used. PTFE-Based PCBs By Rich Trine Technical Service Manager Petersburgh, NY – Tel: 800-833-1805 Fax: 518-658-3988. Here, we use tan δ = 2 × 10 −4 at 4 K. 2. 0010 to 2. The dielectric constant of RT/duroid 5870 and 5880 laminates is uniform from panel to panel and is constant over a. TC600 laminates best-in-class thermal conductivity and mechanical robustness enable printed circuit board (PCB) size reduction. It is a hemispherical skin of microwave-transparent material of radius R and thickness t, supporting a pressure difference, Δp between its inner and outer surfaces. A new kind of ZrTi2O6 filled polytetrafluoroethylene (PTFE) microwave composite substrates was fabricated through the hot-pressing process. Among above composites, the PTFE/SiO 2 composites have low dielectric constant, dielectric loss and low CTE. 2 (1. But the disadvantages such as low mechanical strength and high liner coefficient of thermal expansion (CTE) limit its application. Megtron 6’s electrical properties are competitive with PTFE–based materials, but with improved processability. 5. Polyolefin, irradiated. Download : Download high-res image (357KB)Furthermore, this substrate also displayed low loss with loss tangent of 0. PTFE L-5 and PTFE JH-220 powders showed good dispersion in the PBS matrix, and PTFE FA-500 powder underwent fibrillation during the melt blending process. 5" 0. Based on the report by Xia and Zhange,. stant ("0) and the dielectric loss tangent (tan ) by the following equation (1). 18), and decreased dielectric loss (0. signal and includes both dielectric and dc-conductivity losses. Figure 2 shows the relationship between the dissipation factor vs. Dielectric: Solid Polytetrafluoroethylene (PTFE) Shield (Outer Conductor): Double Silver Covered Copper Shields; Jacket: Flourinated Ethylene Propylene (FEP) Type IX per MIL-C-17; RG 400 Diameter. Step 2: Select the membrane and housing material for your application. If tanD is zero, there is no loss due to dielectric. Relative permittivity is the factor by which the electric field between the charges is decreased relative to vacuum. 3 respectively. 2. This paper presents a fast and easy to use method to determine permittivity and loss tangent in the frequency range of 75 to 325 GHz. The reason for increasing loss tangent with filler loading is attributed to the relatively high loss tangent of the particulate filler compared to that of the PTFE matrix. 6. Teflon is the brand name that Dupont Corporation uses for its PTFE materials, and it is so well-known that people use Teflon PCB to refer to PTFE substrate PCBs used for. However, it is widely used in different fields to measure various types of material properties, such as mechanical, electrical, magnetic, or chemical properties. Test Methods The loss tangent is then defined as the ratio (or angle in a complex plane) of the lossy reaction to the electric field E in the curl equation to the lossless reaction: Solution for the electric field of the electromagnetic wave is where: ω is the angular frequency of the wave, and λ is the wavelength in the dielectric material. 4 for all desired frequencies. For example, loss tangent of HRFZ-Si with resistivity 10 kOhm*cm at 1 THz is 1. 8" L=8. 41 Coefficient of Thermal Expansion 17 18 Y ppm/˚C --55˚C to 288˚C IPC TM-650 2. ; Contact Us Have a question, idea, or some feedback? We want to hear from you. The loss tangent is given by:. Dissipation Factor is a dimensionless measure and hence no units. 1. This carefully controlled ratio provides a higher dielectric constant (Dk) range and better dimensional stability and. Compared to traditional dielectric resonator loaded metal cavity method, it has advantage of small sample size (*2–3 orders of magnitude smaller than the old method), and much higher sensitivity to measure small loss tangent values as small as 10-5 at around 7 GHz bandPTFE- substrate” and relatively insensitive to based composites for use as a printed circuit board substrate is designed to provide enhanced heat-transfer through “Best-In-Class” thermal conductivity, while reducing dielectric loss and insertion loss. The dielectric constant of the presented stack up remains stable around 4. The dielectric constant and dielectric loss of the PTFE substrate was obtained by testing at 1 GHz and 10 GHz, respectively. Hence, in this paper, PTFE and spherical CNT were chosen as polymer matrix and ceramic filler, respectively. Loss tangent (tan (δ)) is a measure of signal loss as the signal propagates down the transmission line. Dielectrics with low. Values presented here are relative dielectric constants. 1 and low loss tangent because of the neutralization of dipole moment exhibited by C-F bonds. Resonac considers the difference between SFR and LCP as the difference in dielectric loss based on Dk and Df. Low loss, low density dielectrics typically range in dielectric constant from 1. 1 Lossy Dielectrics. The Difference Between PCB Core vs. 55, a loss tangent less than 0. 4 1 Introduction 6 2 Grades, supply form, color range, quality assurance 8 3 Physical properties 34 3. 00022. It can be seen that PTFE–Mg 2 SiO 4 nanocomposites shows higher loss tangent as compared to corresponding microcomposites. This measurement method allows us to determine the permittivity and the loss tangent of homogeneous materials. For example, teflon (a. The changing of dielectric constant (εr) and loss tangent (tanδ) were similar to that of the moisture absorption in a manner. The storage modulus (G′), complex viscosity (η*) and loss angle tangent (tanδ) versus angular frequency (ω) are plotted in Fig. e. 0021 E-2/105Loss Tangent – Approximately 0. 0003) and stable dielectric constant (ε r = 2. This increase is expected since glass has a higher Dk than LCP. [Dally] Advanced Board Dielectrics 32 ~1. 5 S/m. 1. Polytetrafluoroethylene (PTFE) has an extremely low loss tangent (tan δ = 0. 14) The term tan d is called loss tangent (dissipation factor or loss factor) and it representsThe fluoropolymer in Pyralux® TK is chemically similar to the PTFE fluoropolymer utilized in rigid high speed laminates and standard procedures to drill and activate such boards should be applicable. When δ is low valued then it is related to loss tangent (the ratio of imaginary and real parts of permittivity) by δ ≈ tanδ ×103 milliradians. Permeability (electromagnetism) In electromagnetism, permeability is the measure of magnetization produced in a material in response to an applied magnetic field. The loss tangent is slightly high at a higher volume concentration of CB; also, the same effect is observed at a higher frequency range. The dissipation factor remained constant, being about 2 × 10 −5. PTFE Standard Compound. The effect of loss tangent on properties of dipole antenna was studied for values 0. @ 2 GHz B. 3 Properties under impact stress 40 3. Just follow these four easy steps: Step 1: Match your application with the appropriate pore size. @ 2 GHz. 008") Dielectric Diameter: 0. Other properties such as electrical, mechanical, physical, thermal and chemical resistance are listed as well as properties particular to the various forms such as films, fibres a. The resultant loss tangent of epoxy resin–barium titanate composite at 5 GHz is shown in Fig. Polytetrafluoroethylene (PTFE), commercially known as Teflon, is a semi-crystalline fluoropolymer. Phys. It can be seen that the PTFE/recycled BRS composite shows a lower dielectric constant, loss tangent, moisture absorption and CTE than the. % untreated SiO 2 filled PTFE composite has a dielectric constant of 2. 44 × 10 −3, respectively, by the improved free-space. Dielectric Loss =. 1. Hence, in this paper, PTFE and spherical CNT were chosen as polymer matrix and ceramic filler, respectively. /. k. 008%) and temperature coefficient of dielectric constant (−18. Loss tangent can be calculated using the following formula:. Roy J. Rogers materials have high parameters (loss tangent, dielectric constant, etc. The more common compounded PTFE grades are filled with glass fibre, bronze, graphite, carbon. PTFE Standard Compound. PTFE is chosen as polymer matrix because of its excellent dielectric properties (low relative permittivity∼2. 5-10. a. RO4350B laminates provide tight control on dielectric constant (Dk) and maintain low loss while utilizing the same processing method as. 4 to 3. @ 10 GHz. 01 Tg value: Low (~130 °C) and high (~180 °C) options available Thickness values: As low as 2 mil Copper options: Typically.