Browsing by Subject "Power divider"

Now showing 1 - 4 of 4

Open Access
Accurate isolation networks in quadrature couplers and power dividers
(IEEE, 2021) Sütbaş, Batuhan; Özbay, Ekmel; Atalar, Abdullah
When quadrature couplers and power dividers are implemented in integrated circuits, accurate isolation networks can not be realized due to the nonideal resistors and the process variations. We present an isolation network design technique which cancels the resistor parasitic effects and also increases the tolerance to variations in the resistance values. A Lange coupler and a power divider are designed at Ka-band using the proposed accurate and process-tolerant isolation networks. The improvement is analytically shown and empirically verified with our in-house GaN-based microstrip MMIC process. For the coupler, the measured return losses and isolation are better than 20 dB from DC to 40 GHz. The power divider achieves 20 dB return losses and isolation in a fractional bandwidth of 50%. Both devices maintain 20 dB performance even when the variation in sheet resistance is as high as 30%.
Open Access
A high performance acoustic microscope - technical aspects and selected applications
(Springer, Boston, MA, 1986-07) Atalar, Abdullah; Hoppe, M.
Technical aspects of a scanning acoustic microscope with broad frequency coverage (50…2000 MHz) are described. Images demonstrating the capabilities of the microscope are shown.
Open Access
A new surface acoustic wave imaging technique
(Springer, Boston, MA, 1986-07) Atalar, Abdullah; Köymen, Hayrettin
A new type of imaging technique is presented which incorporates focussed surface acoustic waves. Surface acoustic waves are generated on the surface to be imaged by use of conical wavefronts. The conical wavefronts are obtained through the reflection of planar wavefronts from a parabolic cylindrical mirror. An imaging system is built which uses focussed surface acoustic waves in a mechanical scanning arrangement controlled by a computer. The resulting images show subsurface features with diffraction limited resolution.
Open Access
A performance enhanced power divider structure
(IEEE, 2014) Taş, Vahdettin; Atalar, Abdullah
We analyze the bandwidth capability of a divider with a series RLC circuit at the isolation arm. Analytical expressions for optimal component values are given. Bandwidth limiting effect of the pad capacitances of the chip resistors is analyzed. These parasitic capacitors are compensated by the proposed structure. Broadband characteristic of the new divider is verified by experimental results.