A simple method for measuring the relative permittivity of printed circuit board materials

Planar small-size LTE/WWAN tablet computer antenna with eight-band operation

“…In particular, those parameter results are optimized at the same time using the software (Ansoft HFSS) as the following parameters are set: W = 1.5 mm, L = 21 mm. Owing to the FR4 substrate parameters such as the dielectric constant and loss tangent fluctuating with the operating frequency, [45,46] the measured input impedance and resonant modes for the proposed MA are slightly different from the obtained simulation results by setting the substrate parameters such as a relative permittivity of 4.3 and a loss tangent of 0.02 across the operating bands. Next, to more thoroughly understand the excitation of each LTE/WWAN band, Figure 3 illustrates the simulated surface current distributed on the major strips such as the C-shaped parasitic monopole and a multibranch shorted strip at various operating frequencies.…”

A Method for Determining the Dielectric Constant of Microwave PCB Substrates

“…Therefore, there is a need to obtain the accurate dielectric properties of PCB substrates at high frequencies to acquire the frequency response of the substrate material. Several related methods, varying in accuracy and in computational effort, are available in the literature [6][7][8][9][10][11][12][13][14]. One of them is the transmission line method [6,7] in which the scattering parameters of a single transmission line on the substrate are measured and the dielectric constant is then determined.…”

“…Another one is the use of a cavity resonator formed by metallization of all faces of a substrate, and the microwave signal is fed via a small hole. Then, dielectric constant information can be extracted from the resonance frequency expression [7][8][9]. Alternatively, the dielectric constant of substrate can be calculated from the resonance frequency by using a ring resonator [10][11][12][13].…”

Planar compact triple-band monopole antenna for IEEE 802.16m WiMAX application

“…Table 1 shows the related results for comparison where f iL and f iH represent the lower and higher cutoff frequencies (RL = 10 dB), respectively, for each operating band (i = 1, 2, 3). Since the dielectric constant and loss tangent of FR4 substrate vary with operating frequency, [25,26] the measured resonant frequencies and input impedance for the antenna slightly differ from the simulated results obtained at some substrate parameter settings such as a relative permittivity of 4.3 and a loss tangent of 0.02 across the operating bands.…”