@article {13_IEEEMWCL_Leal-SevillanoReckJung-KubiakEtAl_SiliconMicromachinedCanonicalTHz, title = {Silicon Micromachined Canonical E-Plane and H-Plane Bandpass Filters at the Terahertz Band}, journal = {IEEE Microwave and Wireless Components Letters}, volume = {23}, number = {6}, year = {2013}, month = {June}, pages = {288-290}, abstract = {In this letter, several bandpass filters operating in the WR-1.5 band (500 to 750 GHz) are presented. The deep reactive ion etching (DRIE) silicon micromachining process is used for the fabrication of the filters. Two canonical filter topologies based on E- and H-plane are implemented. The work presented here has two specific objectives: a) to get important fabrication process parameters, such as tolerances, vertical angles, surface roughness, and repeatability and b) to validate the proper working of the waveguide filters in the terahertz band. These filters do not have any tuning element. Experimental results show better than 10 dB return loss and approximately 1 and 2.5 dB insertion loss (for 6\% fractional bandwidth) for the E- and H-plane topology, respectively. The obtained results are in agreement with fabrication tolerances of 2 micrometers and vertical angles deviations up to 3{\^A}{\textdegree}.}, keywords = {Deep reactive ion etching (DRIE), filter, micromachining, terahertz, WR-15}, issn = {1531-1309}, doi = {10.1109/LMWC.2013.2258097}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6509458}, author = {C A Leal-Sevillano and Reck, T J and Jung-Kubiak, C and Chattopadhyay, G. and J A Ruiz-Cruz and Montejo-Garai, J R and Rebollar, J M} } @article {12_IEEEMWCL_Leal-SevillanoMontejo-GaraiRuiz-CruzEtAl_Low-LossEllipticalResponse, title = {Low-Loss Elliptical Response Filter at 100 GHz}, journal = {Microwave and Wireless Components Letters, IEEE}, volume = {22}, number = {9}, year = {2012}, month = {September}, pages = {459 -461}, abstract = {The design, method of fabrication and experimental validation of a pseudo-elliptical four-poles asymmetric response filter at 100 GHz with 10\% of fractional bandwidth is presented. The designed filter is part of an image radar system and must fulfill stringent specifications. The proposed topology and method of fabrication improves the out of band rejection above the pass band in comparison with other classical structures, while keeping a low insertion loss level. A two-fold geometry for implementing a transmission zero is proposed, avoiding the excitation of the first higher order mode and easing the manufacturing without any tuning element. A low-cost milling process is used for the fabrication of the device. The final design fulfills the desired specifications and presents 0.6 dB of insertion loss level at 100 GHz. The excellent agreement between simulations and measurements at this frequency band in both, return loss and insertion loss, is pointed out.}, keywords = {Asymmetric, band-pass filters, elliptic filters, extracted pole, Fabrication, fabrication method, filter, filtering theory, fractional bandwidth, frequency 100 GHz, higher order mode, image radar system, Insertion loss, loss 0.6 dB, Loss measurement, low insertion loss level, low loss, low-cost milling process, low-loss elliptical response filter, microwave filters, millimetre wave filters, Milling, out of band rejection, pseudo-elliptical four-poles asymmetric response filter, Radar, return loss, transmission zero, two-fold geometry, W-band}, issn = {1531-1309}, doi = {10.1109/LMWC.2012.2212237}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6268297\&tag=1}, author = {C A Leal-Sevillano and Montejo-Garai, J R and J A Ruiz-Cruz and Rebollar, J M} }