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In this paper, we have designed and fabricated the waveguide voltage controlled oscillator (VCO) at 94 GHz, which consists of a GaAs Gunn diode, a varactor diode, and two bias posts with low pass filter (LPF), and a Magic Tee for FMCW radar. The cavity is designed for a fundamental mode at 47 GHz and operated at second harmonic of 94 GHz center frequency. The fabricated VCO has 640 MHz bandwidth, 505 MHz linearity with 2%. The VCO operates at 93.9 GHz with phase noise of -102.79 dBc/Hz at 1 MHz offset and power of 11.34 dBm. The W-band VCO has phase noise better than -100 dBc/Hz.

In this paper, we designed and fabricated waveguide voltage controlled oscillator (VCO), which have a center frequency of 94 GHz using the GaAs Gunn diode, varactor diode, and two bias posts with low pass filter (LPF). The cavity is designed for fundamental mode at 47 GHz and operated second harmonic VCO of 94 GHz center frequency. The fabricated VCO has 1.74 GHz bandwidth, 671 MHz linearity for 2.28% and 14 dBm output power. The highest output power is 15.58 dBm at 94.38 GHz.

In this paper, a design of compact W-band planar Quasi-Yagi antenna is presented. The proposed antenna is fed by 50 Ohm coplanar waveguide with a broad-band balun in order to convert from unbalanced grounded-coplanar waveguide (G-CPW) mode into balanced coplanar strip line (CPS) mode. This antenna is realized on a high dielectric constant substrate, GaAs-relative dielectric permittivity of 12.9, that's compatible with active devices and circuits. Using the truncated ground plane as a reflector, the proposed antenna has a broad relative bandwidth of 18.07% with its return loss better than -10 dB, front to back ratio is 15.6 dB and 6.08 dBi of gain at 94 GHz. This antenna can be widely applied in wireless communication systems, active phased array antenna or millimeter-wave imaging systems.

Right internal jugular vein catheterization is performed frequently as central venous catheterization by the landmark method. This procedure, however, might prove difficulty due to anatomic variations or thrombosis of internal jugular vein. We failed to catheterize right internal jugular vein by the landmark method in 70-year-old female patient. And then, we detected right internal jugular vein thrombosis by ultrasound scan. Left internal jugular vein catheterization was performed by the ultrasound guided technique. Central venous catheterization has possibility to fail despite several attempts by the landmark method. Then, ultrasound guided approach is a good choice to aid central venous catheterization when difficulties or complications have been encountered.

Anaphylaxis is one of major causes of morbidity and mortality during anesthesia. Muscle relaxants are the most common cause of anaphylaxis during anesthesia. A 54-year-old woman was scheduled for thyroidectomy. She had no history of allergy and had never previously undergone general anesthesia, Lidocaine, propofol and vecuronium were injected sequentially to induce general anesthesia. Two minutes after the vecuronium injection, severe hypotension, tachycardia and bronchospasm developed, and delayed skin rashes appeared. The patient recovered without any significant complications after immedi ate proper intensive care. The operation was delayed and a skin test was performed on the 7 th day after discharge. She revealed a positive skin test for vecuronium. The anesthesia was re-induced without muscle relaxant and maintained with propofol and remifentanil infusion. Surgery was completed uneventfully, and the patient recovered without any adverse reaction. (Korean J Anesthesiol 2008; 55: 613～7)