Handbook for Basics

[GNSS+Satellite phone (GMSS)

- GMSS: Inmarsat, Globalstart, Iridium, Thuraya

- Inmarsat BGAN coverage:

서비스명	주파수(MHz)	편파
Iridium	1621-1627	RHCP
Inmarsat	1525-1661	RHCP
Thuraya	1525-1661	LHCP
Globalstar	1610-2500	LHCP

[THz VNA Performance

1. VDI

[Millimeter-Band Rectangular Waveguides

- N.M. Riddler, "Towards standardized waveguide sizes and interfaces for submillimeter wavelengths"

- J.L. Hesler, "Recommendations for waveguide interfaces to 1 THz"

[Low-Loss Dielectric Mateirals

R. Hosono, "Development of LCP-based millimeter-wave devices", Fujikura Tech. Rev., 2018

[Coaxial Cable Loss

M. Moradian, "Investigating the effect of foam properties on the attenuation of coaxial cables with foamed polyethylene dielectric,"

2. Foam dielectric-filled coax

M. Moradian, "Changes in signal transmission speed in coaxial cables through regulating the foam structure of the polyethylene dielectric section," Polyolefins Jour., 8(1), 2021.

[Microwave Network Theory

1. Network Parameter Convertion

- D.M. Pozar, Microwave Engineering 4e, 2012.

2. D.A. Frickey, "Conversions between S, Z, Y, h, ABCD and T parameters which are valid for complex source and load impedances", IEEE T-MTT, 43(1994).

3. P. Miazga, "Generalized linear network analysis method based on the transfer scattering approach," IEEE T-MTT, 72(2024).

[Coaxial Connectors

1. B. Gore, "Are 1.0 mm precision RF connectors really required for 224 Gbps PAM4 verification?" DesignCon 2024.

- Coaxial cable velocity factor: 0.7-0.8 = 1/√ε_r

- Discontinuity-induced TE₁₁-mode resonance

(086 cable, 20 mm)

Modal impedance discontinuity

Insertion loss plot shows a narrow band resonance peak at the cutoff frequency

2. B. Williams, "Overmoding transission characteristics of Type-N connector 7mm line between 18 and 26.5 GHz," ANAMET Report 044, 2004.

- 7mm coaxial cable cutoff frequencies

- Cutoff wavelength vs D/d

- TE11 mode cutoff formula

c = 2.3026, m=1, (c + 1)χ₁₁ = 2.0413

- Adapter insertion loss

Bead resonance spike between 18 and 19 GHz, 20.9, 21.8, 24.5 GHz

See, J F Gilmore, "TE11 mode resonances in precision coaxial connectors," General Radio Experimeter, pp 10 – 13, August 1966.

- Conujate match condition → Bead resonance

- Bead dielectric, TE11 mode above 14.47 GHz, bead width 2 mm, wavelength in dielectric at 15 GHz 2cm.

- Input impedance to the left of the bead: Presents a conjugate match to the right.

- This will generate TE11 mode in the bead but will be cutoff in the air-filled line.

- This is sometimes referred to as a 'ghost mode' in the world of dielectric measurement.

- The above was investigated, from 14 to 19.5 GHz, by calculating the impedance either side of a particular bead support. Results are given in Figure 7, below, where the reciprocal of the sum of the impedance, either side of a bead is plotted against frequency.

- The calculations are sensitive to dimensions, in particular, the width of the bead and the dielectric constant (relative permittivity).

- The big question is if the spikes represent the TE11 resonating within the bead, why does it not continue to propagate and cause more pronounced effects above the cutoff?

- Reflection coefficient

- Bead support structure

3. Extended-freqncy SMA connectors

R. Fuks, "SMA connectors with extended frequency range," Microw. J., 2007

- Designed in late 1950s for 0.141" semi-rigid cable. Max. freq. 12 GHz (initial)

- Design maturized for 18 GHz limit

- Compatible with 3.5 mm (36 GHz max.), 2.9 mm (SMK, 46 GHz max.) connectors

- TE11 mode cutoff

fc = 7.514/[(D+d)√εr] (GHz), D and d in inches

HFSS simulation: SMA, contact diameter 0.050", Teflon diameter 0.1625"

- Premer SMA connector: Designed by Astrolab, 27 GHz max., Bead effective dielectric constant 1.73

Thick-wall SMA plug connectors

Connection between thick wall SMA plug and Premier SMA jack

4. "The importance and role of RF coaxial connector pin height and its impact on electrical and mechanical performance"

Mating interface: For mating male and female connectors. Polarized (male, female)

Contact: Center conductor in a connector. Pin (mating pin; male contact) and socket (female contact; spring fingered; heat treated beryllium copper) configuration

Female connector

Male connector

Pin height (=length); Mating pin has a shoulder

Connector reference planes: Best performance with the smallest gap between the pin shoulder and the socket end.

Pin mating (or contact) gap: At high frequencies, it causes reflection

Pin tip: Has a characterized taper

SMA connector

TNC connector

N connector

QMA connector

Connector interface

Connector guaging requirements: dimensions

Captivated contacts

Non-captive contacts

Captivation methods: To hold center conductor within a connector; Epoxy, dielectric beads (machined or molded; PEEK, Ultem, Torlon, Vespel; high strength with good dielectric properties)

5. B. Fernald, "Online spotlight: RF connector selection guide," Microw. J.

[Circular Waveguide Modes

- TE11 mode and easily-excited modes

- Modes not excited along with TE11 mode

- Example:

[CST Studio Suite

1. High Accuracy Simulation

- Meshing Modes: Use EFPBA

https://loco.lab.asu.edu/loco-memos/edges_reports/tom_20141111_part2.pdf

- Adaptive Mesh Refinements

[Error Statistics

- Standard deviation (SD) measures the dispersion of a dataset relative to its mean.

- The standard error of the mean (SEM) measures how much discrepancy is likely in a sample's mean compared with the population mean.

[Cutoff Frequency, Waveguide

- Rectangular Waveguide

[Guided Wavelength

[Polarization

Ref: Linear to circular polarization conversion using microwave hybrids for VGOS (2-14 GHz)

https://forum.amsat-dl.org/cms/index.php?file-download/4225/

https://ieeexplore.ieee.org/document/6086096

[VNA Block Diagram & Performance

- Agilent PNA Microwave Network Analyzer: 10MHz - 20, 40, 50, 67 GHz ; E8362B, E83363B, E8364B, E8361A

Ref: https://www.keysight.com/us/en/assets/7018-08817/data-sheets-archived/5988-7988.pdf

[Determinant of a Matrix

When calculating a matrix determinant using cofactor expansion, you can choose to expand along any row or column of the matrix.

[Lossless Reciprocal Two-Port

- Ref

- Ahn

S11 = 0.1 (20°), S22 = 0.1 (30°), S21 = 0.995(70°)

S11 = 0.2 (20°), S22 = 0.2 (-20°), S21 = 0.9798(45°)

- Ref: Amakawa, on the choice of cascade de-embedding methods ...

The most general description of a 2-port de-embedding problem involves a 4-port as the mbedding network (Fig. 1).

- Ref: H. J. Eul, experimental results of new self-calibration procedures ...

The calibration of network analyzers at their measurement ports is common to enhance measurement accuracy. A well known method is the 12-Term procedure [1], [2]. As it employs the standards Thru, Match, Short and Open, it is sometimes called TMSO procedure. In contrast to other procedures

[3] (TSD = Thru, Short, Delay) and [4] (TRL = Thru, Reflect, Line) the 12-Term procedure only depends on fully known standards.

While having the advantage of employing partly unknown standards, TRL and TSD have the shortcomming that the electrical length of the line must be different from multiples of the half-wavelength, resulting in a lower bandlimit and periodically repeating frequency ranges of poor performance.

A family of new self-calibration procedures is proposed in [6] allowing for a higher number of unknown parameters in the standards.

The drawback of TRL and the TSD, the limited bandwidth, has been overcome

with the xAx- and xMx-types, since they are on principle of unlimited bandwidth.

Based on a general theory for network analyzer calibration two families of calibration

procedures have been presented, actually the Txx-procedures (TAN, TAR, TAS, TLN,TLR, TLS, TMN, TMR, and TMS) and the corresponding Lxx-procedures (LAN, LAR, LAS, LLN, LLR, LLS, LMN, LMR, and LMS).

- Hayden, an enhanced Line-Reflect-Reflect-Match calibration

When computing the LRRM calibration the system relies on uniqueness of the reflect standards to provide information (equations) to help solve for the error-terms (unknowns). A problem may be observed when using probe tip reflect standards and the thru line is approximately one-quarter wavelength long. At this frequency (and odd multiples) ideal open and shorts located at the probe tip are contributing the same information, preventing a proper cal (resonant spikes are observed on the open verification plot). The LRRM algorithm is largely computed with a center-of thru reference plane. Re-computing these (probe-tip) reflects for their apparent value at a center-thru reference plane results in impedances with zero real part and opposite sign imaginary part when the resonant spikes occur. It is apparent from experimentation that the two reflects are providing the same information in this situation. The solution to the system given by (13) and (19) is singular and the denominator of (20) goes to zero.

- Virone, Extended through-short-delay technique ...

Conversely, thru-reflection-line (TRL) and through-short-delay (TSD) techniques are widely recognized as the most precise means of calibration of VNAs with connectable waveguide ports since they fully exploit the self-calibrating capabilities of the standards adopted in the calibration process [8]. Moreover, multiple-line TRL methods can be adopted in order to widen the bandwidth and to improve the accuracy of the calibration [9] of single-mode and multimode VNAs [10].

- Degerstrom, US20110298476A1

Symmetric fixture

Thru, open/short

Thru-1, Thru-2

ABCD matrix, Levenberg-Marquardi optimization