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In this paper, a scaled measurement system designed for wireless channel characterization is proposed and discussed, and experimental results are reported. The system consists of a vector network analyzer, miniaturized W-band transmitter and receiver probes, scaled buildings, and a precise computer-controlled positioner. The scaled propagation meas...
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... what follows, the block diagrams and main components of the SPMS are first presented, and then the design, fabrication, and performance of individual elements will be described. The overall system specifications are demonstrated last. Fig. 1 shows the main components of the -band ...
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... and are the characteristic impedance of the CPW line and port impedances, respectively. In this design, both are chosen to be 50 . In (3), , , and are the center, lower cutoff, and higher cutoff angular frequencies. A photograph of the fabricated filter is shown in Fig. 8. Fig. 10 shows the simu- lated and measured filter responses. The magnetic current con- cept is used in the MoM simulation for fast computation and more accurate excitation of CPW structures. As such, conduc- tive loss is not modeled. This effect was considered in simu- lation by extracting inductors and CPW line parameters from measured ...
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... measured filter responses. The magnetic current con- cept is used in the MoM simulation for fast computation and more accurate excitation of CPW structures. As such, conduc- tive loss is not modeled. This effect was considered in simu- lation by extracting inductors and CPW line parameters from measured results and was used in the simulations. Fig. 10 shows the filter rejection at and to be more than 35 dB. The closest undesired harmonic to the RF signal, which is the upper sideband of the up-converted IF signal GHz , is also at least 30 dB attenuated through two such filters at the transmitter and receiver probes totally. This ensures that the SPMS is able to measure fading depth ...
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... at the LO frequency, which acts as an open circuit for the LO signal and a short circuit for the IF and RF signals, is also placed at the LO side of the subharmonic mixer to block IF and RF signals leakage to the LO port. The subharmonic mixer circuit is optimized for the best conversion loss, large signal matching at all ports, and minimum size. Fig. 11 shows the subharmonic mixer layout with the IF and the first stage of the RF filters. Wire bonds are placed at all discontinuities to suppress undesired slot modes on the CPW ...
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... simulation and measured output RF power of the up-con- verter and conversion loss are shown in Figs. 12 and 13, respec- tively. As can be seen, the maximum up-converted signal power is sufficient to provide the RF amplifier with the required input power for maximum output. The maximum spurious level of the RF signal in the SMPS is shown in Fig. 14, where it is shown that the average maximum spurious level is 40 dBc. This allows for measurement ...
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... simulation and measured output RF power of the up-con- verter and conversion loss are shown in Figs. 12 and 13, respec- tively. As can be seen, the maximum up-converted signal power is sufficient to provide the RF amplifier with the required input power for maximum output. The maximum spurious level of the RF signal in the SMPS is shown in Fig. 14, where it is shown that the average maximum spurious level is 40 dBc. This allows for measurement of fading depths as low as 40 dB. The down-con- verter used in the receiver probe has the same topology as the up-converter with similar performance characteristics. ...
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... the up-con- verter and down-converter, a -band amplifier is used in each probe. The amplifier chip is mounted on the circuit using silver epoxy. The input and output of the chip and dc contacts are con- nected to the circuit using gold wire bonds. In the desired RF frequency range, the amplifier has a gain of 27-29 dB and a noise figure of 4 dB. Fig. 15 shows the amplifier gain, noise figure, and its input and output return ...
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... conditions. In order to accomplish this properly, the transmit and receive antennas should have broad beam patterns. A monopole antenna is chosen for this purpose. As the monopole above a fi- nite ground surface of the package is not automatically matched, a quarter-wavelength transmission line is used to match the an- tenna to the circuit. Fig. 16 shows the antenna and matching line between the antenna and RF amplifier. The simulated gain patterns of this antenna, above the packaged circuit, at -and -planes are shown in Fig. 17(a) and (b), respectively. ...
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... above a fi- nite ground surface of the package is not automatically matched, a quarter-wavelength transmission line is used to match the an- tenna to the circuit. Fig. 16 shows the antenna and matching line between the antenna and RF amplifier. The simulated gain patterns of this antenna, above the packaged circuit, at -and -planes are shown in Fig. 17(a) and (b), respectively. ...
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... Tool Room Model CNC machine with tolerances less than 2.5 m. The fabricated circuit on the quartz substrate was diced using an automatic dicing saw and then, together with 2.4-mm coaxial connectors for the IF and LO ports, was assembled with the aluminum package. The LO and IF 2.4-mm connector pins are connected to the circuit using silver epoxy. Fig. 18 shows the packaged probe against a ...
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... precise three-dimensional (3-D) printer is used to make scaled buildings. This printer can use different materials and can make any building with any desired fine features. Any standard computer-aided design (CAD) software can be used to draw the buildings and export the geometry file for the 3-D printer. Fig.19 (a) and (b) shows the CAD model of a scaled building and actual building printed by the 3-D printer. Fig. 20 shows the first version of a scaled city block with simple building struc- tures. It can be seen that the scaled city has a flexible grid, which is designed to help make an arbitrary arrangement of the blocks including roads, ...
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... to each motor sends the position and velocity data back to the computer. The computer uses this information to control the probe movement. The system placement is accurate within 0.25 mm. This is acceptable accuracy even for fast fading mea- surements at the RF frequency range (90.8-92.8 GHz) at which the wavelength is approximately 3.3 mm. Fig. 21 shows the block diagram of the -table ...
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... 60-GHz channel characteristics have been well studied in the past. References [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] are some of most recent experimental work in uncovering the behavior of the channels . It has been noted that the channels around 60 GHz do not exhibit rich multipath, and the non-line-of-sight (NLOS) components suffer from tremendous attenuation. ...
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... Thus, the AR coefficients, , can be calculated as follows (17) The time delay for each impulse response can be calculated using (18). Finally the amplitude for each ray can calculate using the relationship . ...
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