Test Report | IceConeFeed v2.1 | S-Band helix 2.2 turns, 1.4mm wire

This report provides an overview of a conducted antenna test, including a description of the antenna under test, the measurement setup, the procedure followed during testing, and the generated data products.

Antenna Under Test (AUT)

The antenna under test is described in the Antenna Under Test section.

All measurements are recorded with respect to the antenna coordinate system, defined as follows:

z-axis along antenna boresight
y-axis through mounting hole center
x-axis completes right-handed coordinate system

Test Setup

The measurement was carried out in a controlled environment with the following equipment:

Vector Network Analyzer (VNA): Sysjoint SV4401A
Positioning System: nolle.engineering Full Spherical Antenna Tracker
Reference antenna: nolle.engineering Standard Gain Horn
Cable loss compensation was applied using calibrated measurements.

Test Conduction

The following procedure was followed:

Calibration of end-to-end RF path (Open, Short, Load, Through)
Mounting of the AUT on the antenna tracker.
Execution of S11 and S21 measurements across the specified frequency band and full spherical coverage.
Vertical and horizontal orientation of the standard gain horn for gain reference.

Measurements

The following types of data were collected:

Return loss (S11)
Transmission gain (S21)

Measurements were recorded in raw format for further analysis.

Data Products

The following data products are included in this report and can be accessed via the navigation sidebar.

Antenna Under Test
Measurement Trajectory
Radiation Pattern 3D
Axial Ratio Pattern 3D
Radiation Pattern 2D
Maximum Gain
Half Power Beam Width (HPBW)
Standing Wave Ratio (SWR)
Data Export

Loading data…

The processed measurement results are available as a curated SQLite database alongside this report. It contains the three tables described below and is suitable for direct use in Python, MATLAB, Excel, or any SQLite-capable tool. Raw S-parameter time-series and internal trajectory tables are not included.

↓ Download measurements.sqlite

Schema

`vertices`

One row per spatial sample point. The three components form a unit vector on the sphere pointing from the antenna toward the measurement direction. Boresight of the antenna under test is (0, 0, 1).

Column	Type	Unit	Description
`id`	INTEGER	—	Primary key; referenced by `results_by_vertex.vertex_id`
`x`	REAL	dimensionless	Unit vector x-component
`y`	REAL	dimensionless	Unit vector y-component
`z`	REAL	dimensionless	Unit vector z-component (z = 1 → boresight)

`results_by_vertex`

Computed RF quantities at every sample direction and frequency. Join with vertices on vertex_id = vertices.id to obtain the spatial coordinates.

Column	Type	Unit	Description
`vertex_id`	INTEGER	—	Foreign key → `vertices.id`
`frequency`	REAL	Hz	Measurement frequency
`axial_ratio`	REAL	dB	Axial ratio at this direction and frequency
`axial_ratio_linear`	REAL	dimensionless	Axial ratio (linear scale)
`gain`	REAL	dBi	Total gain (polarisation-combined)
`gain_lhcp`	REAL	dBic	LHCP gain
`gain_rhcp`	REAL	dBic	RHCP gain
`gain_linear`	REAL	dBi	Linear-polarisation gain
`angle_max_gain`	REAL	deg	Angle from boresight to total peak gain direction
`angle_max_gain_lhcp`	REAL	deg	Angle from boresight to LHCP peak gain direction
`angle_max_gain_rhcp`	REAL	deg	Angle from boresight to RHCP peak gain direction
`angle_z`	REAL	deg	Polar angle of this vertex from the z-axis (boresight)
`swr`	REAL	dimensionless	Standing Wave Ratio (derived from S11)
`impedance_real`	REAL	Ω	Antenna input impedance — real part
`impedance_imag`	REAL	Ω	Antenna input impedance — imaginary part
`admittance_real`	REAL	S	Antenna input admittance — real part
`admittance_imag`	REAL	S	Antenna input admittance — imaginary part

`results_by_frequency`

Aggregated scalar results per frequency: peak gain values, beam directions, and half-power beam widths.

Column	Type	Unit	Description
`frequency`	REAL	Hz	Measurement frequency
`gain_max_dBi`	REAL	dBi	Peak total gain across all directions
`gain_lhcp_max_dBic`	REAL	dBic	Peak LHCP gain
`gain_rhcp_max_dBic`	REAL	dBic	Peak RHCP gain
`max_gain_direction_x`	REAL	dimensionless	Unit vector of total peak gain direction — x
`max_gain_direction_y`	REAL	dimensionless	Unit vector of total peak gain direction — y
`max_gain_direction_z`	REAL	dimensionless	Unit vector of total peak gain direction — z
`max_gain_lhcp_direction_x`	REAL	dimensionless	Unit vector of LHCP peak gain direction — x
`max_gain_lhcp_direction_y`	REAL	dimensionless	Unit vector of LHCP peak gain direction — y
`max_gain_lhcp_direction_z`	REAL	dimensionless	Unit vector of LHCP peak gain direction — z
`max_gain_rhcp_direction_x`	REAL	dimensionless	Unit vector of RHCP peak gain direction — x
`max_gain_rhcp_direction_y`	REAL	dimensionless	Unit vector of RHCP peak gain direction — y
`max_gain_rhcp_direction_z`	REAL	dimensionless	Unit vector of RHCP peak gain direction — z
`max_gain_angle_z`	REAL	deg	Polar angle of total peak gain direction from boresight
`max_gain_lhcp_angle_z`	REAL	deg	Polar angle of LHCP peak gain direction from boresight
`max_gain_rhcp_angle_z`	REAL	deg	Polar angle of RHCP peak gain direction from boresight
`hpbw_angle`	REAL	deg	Half-Power Beam Width — total
`hpbw_angle_lhcp`	REAL	deg	Half-Power Beam Width — LHCP
`hpbw_angle_rhcp`	REAL	deg	Half-Power Beam Width — RHCP

Example Queries

Peak LHCP gain vs frequency:

SELECT frequency / 1e6 AS freq_MHz,
       gain_lhcp_max_dBic
FROM   results_by_frequency
ORDER  BY frequency;

Full gain pattern at a specific frequency:

SELECT v.x, v.y, v.z,
       r.gain_lhcp,
       r.axial_ratio
FROM   results_by_vertex r
JOIN   vertices v ON r.vertex_id = v.id
WHERE  r.frequency = 1575420000
ORDER  BY r.vertex_id;

Export gain pattern to CSV (Python):

import sqlite3, pandas as pd

con = sqlite3.connect("measurements.sqlite")
df = pd.read_sql("""
    SELECT v.x, v.y, v.z,
           r.frequency / 1e6 AS freq_MHz,
           r.gain_lhcp, r.gain_rhcp, r.axial_ratio
    FROM   results_by_vertex r
    JOIN   vertices v ON r.vertex_id = v.id
    ORDER  BY r.frequency, r.vertex_id
""", con)
df.to_csv("gain_pattern.csv", index=False)

Best axial ratio direction per frequency:

SELECT r.frequency / 1e6 AS freq_MHz,
       MIN(r.axial_ratio) AS best_ar_dB,
       v.x, v.y, v.z
FROM   results_by_vertex r
JOIN   vertices v ON r.vertex_id = v.id
GROUP  BY r.frequency
ORDER  BY r.frequency;

How to Open

DB Browser for SQLite — free GUI tool, cross-platform. Open the file, browse tables, and export to CSV with one click. Available at sqlitebrowser.org.

Python — standard library:

import sqlite3

con = sqlite3.connect("measurements.sqlite")
cur = con.cursor()
cur.execute("SELECT * FROM results_by_frequency ORDER BY frequency")
for row in cur.fetchall():
    print(row)

Python — pandas:

import sqlite3, pandas as pd

con = sqlite3.connect("measurements.sqlite")
df = pd.read_sql("SELECT * FROM results_by_frequency", con)

MATLAB:

conn = sqlite('measurements.sqlite');
data = fetch(conn, 'SELECT * FROM results_by_frequency ORDER BY frequency');
close(conn)