Planar transmission line

Figure 9. Examples of planar transmission line structures. Dimensions are as follows b is dielectric thickness, w is line width, and t is conductor thickness.

Non resonant techniques are only of limited use to determine microwave losses with high precision, in particular when the losses are very small. Flowever, for the investigation of nonlinear absorption phenomena (i.e. rf power dependent on surface impedance or loss tangent) by intermodulation distortion measurements broad-band test devices are more common. Typically, a planar transmission line with an impedance of 50 Ohms can be employed for intermodulation... 

Chiolerio, A., Cotto, M., Pandolfi, R, Martino, R, Camarchia, V., Rirola, M., Ghione, G., 2012. Ag nanoparticle-based inkjet printed planar transmission lines for RF and microwave applications considerations on ink composition, nanoparticle size distribution and sintering time. Microelectron. Eng. 97, 8-15. 

A variety of transmission line structures can be fabricated in planar layers of conductor and dielectric (Figure 9). The stripline and offset stripline are best suited for multilayer structures. The offset stripline, with two orthogonal signal layers between a pair of reference voltage planes, eliminates one intermediate plane and achieves higher characteristic impedance for a given dielectric thickness than do two stripline layers but increases the possibility for crosstalk between layers. 

Planar resonators and microstrip and coplanar transmission lines represent the passive elements in almost any integrated circuit technology at first, on chip integration in socalled mmics (monolithic microwave integrated circuits) with SiGe or m/v semiconducting active... 

Planar inductors are suited for both thick-film, thin-film, and LTCC applications. Typical members of this group are meander and spiral inductors (Figure 9.22). Meander inductors offer the lowest inductance vs. size. Their inductance value is determined by tiie length and the unit line inductance. Because of the adverse magnetic-field orientation of adjacent line segments, there is no increase of the overall inductance [6]. The inductance is directly proportional to the meander lengtii. Meander inductors are usually used for low inductances and delay lines. Because the meander is more or less a transmission line, the distributed character is dominating in most cases. 

Both thin- and thick-film technology allow planar microstrip or coplanar transmission lines. However, requirements on line and coupling-gap accuracy do not always permit traditional screen printing. Etching techniques or photosensitive paste systems offer a potential solution. LTCC provides more design freedom. Impedance-matched line transitions (e.g., from microstrip to stripline or to an embedded waveguide) are possible. 

Piezoelectric MIcrodlspenser, Figure 1 Equivalent circuit modeling of (a) planar, thickness-polarized, thickness-vibrating piezoelectric transducers using (b) a simple lumped-element Van Dyke model and (c) a more complex transmission-line model. A model of a piezoelectric microdispenser (d) may be formed by connecting the output terminals to the equivalent circuit model of the remaining components (e)... 

Dq being the diffusion coefficient of the oxidized species and Dg that of the reduced species. Treatment of this system assumes that we can write the equivalent circuit of kinetic and diffusion control as shown in Fig. 2.32, where the diffusion component of the impedance is given by the Warburg impedance W. It should also be noted that the derivation applies to a planar electrode only. Electrodes with more complex geometries such as porous electrodes require a transmission-line analysis. 

Laser ultrasonic transducers are truly non-contact devices which effectively avoid acoustic coupling problems (e.g. damping in the transducer and couplant reflection and transmission losses at the interface). Most laser ultrasonic devices have been used for excitation and detection of bulk elastic waves in point source or planar geometry, but also surface acoustic (Rayleigh or Brillouin) waves. Unlike the bulk wave regime, only one sample side is needed for excitation and detection when surface waves are used. This not only renders the measurements easier, but also avoids the need for an accurate knowledge and uniformity of the sample thickness. In addition, the excitation laser can be focused using cylindrical lenses in order to obtain an excitation line. 

Fig. II. Reflectivity and transmissivity of a planar Fabry-Perot R = 0.8. The transmissivity is indicated by the dash-dot line the reflectivity is indicated by the dashed line.

Fig. 6.30 (a) Schematic illustration of processes of surface-plasmon resontince (SPR) and localized-plasmon resonance (LPR). (b) Photocurrent ratio of a ruthenium dye (N3)-modified nanostructured electrode (SPR) to planar electrodes (LPR) (filled circle), and the transmission absorption spectrum (solid line) of the nanostructured electrode [138]... 

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