The dielectric resonator method is now widely accepted as a precise measurement method for determining the dielectric properties at microwave frequencies. This paper describes the measurement results of ε_r, tan δ and TC_f determined by a round robin test of this method. The resultant measurement errors were Δε_r/ε_r0.10%, Δtan δ0.510⁵ and ΔTC_f0.5 ppm/K, where Δdenotes a standard deviation. The causes of measurement errors and the conditions to improve the measurement accuracy are discussed.

An image type resonator method is proposed as a method to evaluate precisely the temperature dependence of dielectric material. At first, the temperature coefficients of the resonant frequencies, TC_f are measured separately using the shielded dielectric resonators of three types; that is a parallel plate type, and an image type, and a MIC type resonator. Secondly, an intrinsic temperature coefficient of the resonant frequency TC_f0, which is defined as the temperature coefficient of a resonant frequency when all the stored energy is confined inside a dielectric, is estimated from these measured TC_f. Actually, the TC_f0 values of a sapphire and (Zr・Sn) TiO₄ rod are estimated from the TC_f values measured for the resonators of three types. As a result, for the parallel plate type, the precision of TC_f0 is about 0.1 ppm/. For the image and MIC types, the errors of about 0.5 ppm/ in the TC_f0 values arise from the errors in the linear expansion coefficients of the resonators, rather than from the experimental errors in TC_f. Then, another image type resonator is designed to estimate TC_f0 within error of 0.1 ppm/. In this design, dimensions of the shielding cavity is determined to reduce the influence of the errors in the linear expansion coefficients on precision of the TC_f0 estimation. Finally, for a (Zr・Sn) TiO₄ ceramic rod, a TC_f0 value estimated from TC_f measured for the image type resonator is obtained with accuracy of about0.1 ppm/.

This paper describes a nondestructive measurement method for complex permittivity of dielectric material at pseudo microwave frequencies. The resonator used in this study has a cylindrical cavity filled with a sapphire material of a well known complex permittivity. The resonator is divided into two parts at the center. A dielectric substrate specimen is clamped with these halves. Relative permittivity εand loss tangent tan δ of the specimen are obtained at 3 GHz using the TE₀₁₁ resonance mode. The accuracy of the present method is evaluated through the comparison of the measured values by the new method with those at around 10 GHz by the conventional empty cavity resonator method. The errors of measurements are smaller than 1% and 110⁵ for εand tan δ, respectively.

An improvement of Q evaluation is discussed. The Resonance Curve Area method was confirmed to give a deviation in the order of 610⁴. The result was three times more accurate than the widely known Q evaluating method which utilizes the cursor function installed in a network analyzer. A discussion is also made on the physical validity of the RCA method. It is shown that the application of the RCA method improves the accuracy of the cavity perturbation method. Actual measurements have shown that the deviation of dielectric constant is less than 1% and that of the loss tangent is less than 3%, in the order of 10⁴. The accuracy of the RCA method was estimated to be three times that of the conventional cavity perturbation technique. The consistency of the perturbation with other methods has also confirmed. The accuracy comparison to more accurate formulae derived from a rigorous solution have shown that the difference is sufficiently small.

A kind of time domain reflectometry using deconvolution and envelope extraction process is presented for measuring microwave resonator characteristics, where data acquisition and data processing are performed entirely in the time domain. The proposed method may be used to characterize resonators which have Q values in the range between a few dozen and several hundred. The major drawback of the time domain measurement techniques is in general considered to be a low frequency resolution. In the proposed method, it is avoided skillfully.

A simple method for separating the dissipation factors associated with both conductor losses and dielectric losses of printed circuit boards in microwave frequencies is presented. This method utilizes the difference in dependence of two dissipation factors on the dimensions of bounded stripline resonators using a single printed circuit board specimen as a center strip conductor. In this method, the separation is made through a procedure involving the comparison of the measured values of the total dissipation factor with those numerically calculated for the resonators. A method, which is based on a TEM wave approximation and uses Green's function and a variational principle, is used for the numerical calculation. Both effective conductivity for three kinds of industrial copper conductor supported with a substrate of polymide film and dielectric loss tangent of the substrates are determined using this method from the values of the unloaded Q measured at the 10 GHz region. Radiation losses from the resonator affecting the accuracy of the separation are discussed, as well as the values of the effective conductivity of metals on the polyimide substrate which is calculated using the above method. The resulting values of the effective conductivity agree with those using the triplateline method within 10%.

In this paper, we discuss an application of range Doppler imaging to measurement of reflected wave intensity from a moving object without using an anechoic chamber. The wave intensity reflected from a metal plate moving in the horizontal direction toward the antenna is typically 40-50 dB higher than that in the case without using the plate, and the estimated radar cross sections for a metal plate and sphere show good agreement with the theoretical value. The measurement of wave absorption by the present method suggests that frequency characteristics of the observed reflection loss are in close agreement with those of the calculated loss. These results show the reliability of the present experimental system and suggest that the method is applicable to wave reflection measurement not in an anechoic chamber but in an ordinary laboratory room.

A simple adapter de-embedding method is presented in a six-port calibration process using only one sliding load and one standard short. Adapter de-embedding is performed to extract the S-parameters of the adapter from the six-port system parameters. The concept of this method is based on the relations between the S-parameters and the Fourier coefficients of the periodic return loss of the adapter. To complete the de-embedding procedure, there are two measurement steps: one is return loss measurement with the sliding load, and the other, sidearm power measurement with the standard short. Using these measured values, unique solutions of the S-parameters are determined. A computer-controlled six-port with 2.4 mm coaxial-type connector was designed for calibration using a waveguide-type sliding load over the frequency range of 8.5-12.0 GHz. Through experiments, the adapter for joining two unlike connector types was measured. Then the reflection coefficients of the adapter with the sliding load measured by the calibrated six-port and those calculated from the S-parameters were compared with each other. As a result, an overall good agreement with standard deviation of less than 0.1% was found at all setting frequencies. One of the main features of the method is that the S-prameters of a two-port as well as the system parameters of a six-port can be determined by means of simple scalar measurement.

This paper discusses the effect of random errors in power meter readings by the six-port reflectometer. By means of six-port techniques, the determination of the reflection coefficient (Γ) of a divice under test is reduced to the problem of finding a common intersection of three circles in the complex plane. Since the intersection usually forms a cluster due to the effect of measurement error, the extraction of a single value from the cluster including the radical center of the three circles is required. Two types of methods are presented for determining Γ. One uses a linear solution for the radical center, and the other is a statistically based nonlinear solution. In order to improve measurement accuracy, the effect of random errors in the sidearm power meter readings and due to the influence of the q-point locations are investigated for each method. By adding a random variation of 0.5% onto each of the three port power ratios, the variance distributions of Γ over the entire area of the Smith chart are simulated for comparison of these two solutions. The three dimensional variance distribution chart reveals that only the nonlinear solution suffers a variance increase shown as a ridgelike peak along the lines of centers of the three circles. As a result of computer simulations, it is clarified that the reflectometer has the property of measurement accuracy dependence on the value of Γ. A new type of six-port model is suggested, which is unlikely to be affected by random errors in the nonlinear solution.

A novel analysis method of the intermodulation (IM) and the noise power ratio (NPR) of multiple-carrier amplifiers is descrided. This method, based on Discrete Fourier Transform, allows an accurate calculation of IM and NPR of the amplifier having multiple carriers by directly using measured single-carrier amplitude and phase characteristics. This method has an outstanding feature in that it can be applied to the general case of n carriers having an arbitrary power level as long as frequency-dependence of amplitude and phase characteristics is negligibly small. Applying this method to the linearized amplifier, a good agreement between measured and calculated results for IM3, IM5, and NPR has been obtained for operation from linear up to saturation, which shows this method would be a good candidate for calculating IM and NPR of multiple-carrier amplifiers.

A semicylindrical microstrip applicator system is proposed and designed, both for microwave heating and for noninvasive temperature estimation, in application to hyperthermia treatment. The experimental results showed that the system functions both as a heating device and as a means of noninvasive temperature estimation. Therefore, electrical switching of these two functions makes the system realize both heating and temperature estimation. These functions reduce the pain of hyperthermia therapy for patients. The system is constructed of a water-loaded cylindrical applicator. Thus, the whole system can be made compact compared to conventional applicators. This improvement allows for various merits, such as realizing a surface cooling effect and decreased leakage of electromagnetic (EM) waves. When the applicator is set as an array arrangement, the system can be used as a microwave heating device. The penetration depth can be varied by adjusting phases of the EM wave radiated from each applicator. The experimental results at 430 MHz showed that semicylindrical microstrip applicators can be expected to be valid for tumor heating at depths within 55 mm. Moreover, by measuring transmission power between the two applicators, the system can be used to estimate temperature inside the medium. The transmission power which was measured in the frequency domain was converted in the time domain. By such a method, temperature distribution was calculated by solving simple simultaneous primary equations. The results of the temperature estimation show that the number of estimated temperature segments which have an error within 0.5 is 28 out of 36. The system can be easily used as a temperature measuring applicator as well as a heating applicator.

Transmission characteristics of CPW bends having various curvatures and a fixed bend angle were measured. It was found that the transmission level shows dips at some particular frequencies, and that the dips are less pronounced as the radius of curvature becomes larger.

C-V and I-V characteristics of an n-MOSFET with Si-implanted gate-SiO₂ of 50 nm are analyzed by using a test device with large equal channel width and length of 100 µm, and discussed for realizing a large hysteresis window of threshold voltage. Interface trap densities change logarithmically from 310¹⁰ to 110¹²cm²eV¹ as the Si-dose at 25 keV increases from zero to 310¹⁶cm². Threshold-voltage changes caused by 25 keV implantaions are as high as 0.2 V. Effective mobilities (subthreshold swings) change from 600 (0.10) to 100 cm²/V・s (0.26 V/decade) as the Si-dose increases from 0 to 310¹⁶ cm² at 25 keV, and both parameters are related with the change of interface trap densities. There is a close relationship between the hysteresis windows of gate current and threshold voltage, and the largest threshold voltage window in a low gate voltage region is obtained for the MOSFET with Si-implantation at 25 keV/310¹⁶ cm².

A new design methodology is proposed and analyzed for the design of ternary logic systems. In the new ternary logic systems, no conversions among radices are required and only the two-state ternary literals associated with the ternary signals are transmitted in the whole system. With the new design methodology, the ternary systems can be realized by the dynamic CMOS logic circuits which are simple and fully compatible with those of the conventional binary logic circuits in process, power supply, and logic levels. A new dynamic differential logic called the CMOS Redundant Differential Logic (CRDL) is also developed to increase the logic flexibility and the circuit performance. Using the new design methodology and the CRDL circuits, the multiplier with redundant binary addition tree is designed in both non-pipelined and pipelined systems. The experimental chip has been fabricated and measured, which successfully verifies the correctness of the logic functions and the speed performance of the designed circuits.

A new built-in drive circuit for superconducting Josephson LSI circuits has been designed and fabricated in a ceramic multichip module. The drive circuit consists of an impedance matching circuit and a DC bias current feeding circuit to supply a two-phase power current to Josephson chips at a microwave frequency. The impedance matching circuit was designed based on a quarter wavelength stripline. A balanced stripline configuration was introduced to reduce the fluctuation of ground potential. Tungsten layers were used to make the drive circuit in a multilayer ceramic substrate of the multichip module. Whole circuit was successfully packed in a volume of 76 mm38 mm1.7 mm. The gain of microwave current were 20 dB around 1.2 GHz and 23 dB around 3.6 GHz, which were in good agreement with the simulated current gain.

The plane wave diffraction by a two-dimensional parallel-plate waveguide cavity with partial material loading is rigorously analyzed for both the E and the H polarization using the Wiener-Hopf technique. Introducing the Fourier transform for the scattered field and applying boundary conditions in the transform domain, the problem is formulated in terms of the simultaneous Wiener-Hopf equations satisfied by the unknown spectral functions. The Wiener-Hopf equations are solved exactly via the factorization and decomposition procedure leading to the formal solution, which involves branch-cut integrals with unknown integrands as well as infinite series with unknown coefficients. Applying rigorous asymptotics with the aid of the edge condition, the approximate solution to the Wiener-Hopf equations is derived in the form suitable for numerical computations. The scattered field inside and outside the cavity is evaluated by taking the inverse Fourier transform together with the use of the saddle point method. Numerical examples of the radar cross section are presented for various physical parameters, and the far field backscattering characteristics of the cavity are discussed in detail. Some comparisons with a high-frequency technique are also given to validate the present method.

A high-efficiency air cooling system is one of the keys to achieving high throughput in an ATM switching system for Broadband ISDN. Our approach is to cool the multichip modules plugged into a planar packaging system by using a two-phase thermosyphon cold-plate with an air-cooled condenser. Physically separating the cold-plate and the air-cooled condenser and connecting item by small diameter pipes is the key to applying this cooling technology to large planar packaging systems to increase volumetric packaging densities. Furthermore, thermosyphon technology allows the heat transfer process to operate without any external pumping power. Therefore this cooling system is regarded an extended high-performance air cooling system. The optimum structure was investigated while focusing on ways to reduce the external thermal resistance. The external thermal resistance between the system's cold-plate and air inlet was measured to be 0.21 K/W at an air velocity of 2 m/s and a cooling duty of 150 watts. Using this external thermal resistance value, we simulated the cooling characteristics of an MCM containing a 44 array of 10-mm-square LSI chips on an alumina substrate measuring 100100 mm. For an allowable temperature rise of 60, simulated thermal resistance was 6 K/W at an air flow of 2 m/s. This allows a power dissipation of more than 160 watts per MCM and a heat flux of 1.6 W/cm². This system will extend the applicability of air cooling to power levels generally considered to lie in the domain of liquid cooling, and thus to the ATM switching nodes for B-ISDN.

Physical optics (PO) is an approximation method for high-frequency scattering and diffraction problems. But PO fields are inaccurate in the shadow region where the source is screened by the scatterer. It has been difficult to extract the mechanism of this error because PO includes numerical integration. In 2-D problems, PO fields are analytically and accurately expressed in terms of PO equivalent edge currents (PO-EECs) which represent the leading contributions of PO original integration. Comparison of PO in this form and geometrical theory of diffraction (GTD) which gives accurate fields in the shadow region, clarifies the cause of PO errors. For a scatterer with a corner, PO errors are mainly due to the rays emanating from the invisible edges. For a curved surface scatterer, the contributions penetrating the scatterer are small and main PO errors generally consist in PO-EECs itself.

A very-high-speed ten-neuron analog neural network LSI chip is fabricated for the first time using super self-aligned Si bipolar process technology. The LSI consists of ten neurons and 100 electrically modifiable synaptic weights. The neural network nonlinear mapping function to solve the four-bit parity problem is successfully demonstrated at 150 mega-patterns/sec. The operation speed of this neural network is, to the best of the authors, knowledge, the fastest yet reported.

We propose a beam tracing frame which shifts together with either the guiding structure or the beam propagation in optical circuits. This frame is adaptive to the beam propagation analysis based on the finite-element method and can reduce the computational window size.

If one of the R, L, or C Parameter of an RLC parallel circuit is changed periodically, under certain conditions, an oscillation called Parametric oscillation occurs. If one of remaining circuit elements is made to change due to an external cause (e.g. an external electric or magnetic field), then the parametric oscillation will experience some modulation. This modulation process and the subsequent demodulation can be exploited to create several types of sensors. In this letter, we describe the features of a new parametric magnetic speed sensor and its application in Induction motor robust control.