**6.1. Reflection coefficient**

The prototype 4 is measured with the Agilent E8364B PNA vector network analyzer, the electronic calibration kit N4693A 2-port ECal-module was used for full-range calibration of the PNA (50GHz).

The reflection coefficient magnitude of prototype 4 is measured and shown in fig. 11, the measurement agreed well with predicted value. Small deviation as frequency higher than 26 GHz, this defect is inherently caused by the failure of the 3.5mm SMA-connector, whose HFrange is cataloged as 18GHz max. The result indicated that the prototype 4 is a SWBradiator because its measured ratio-bandwidth BR is certainly greater than 10:1.

**Figure 11.** SWB-performance: simulated and measured results.

#### **6.2. Far-field radiation patterns**

174 Ultra Wideband – Current Status and Future Trends

antenna with short and long feed.

**6.1. Reflection coefficient** 

**6. Measurements** 

the PNA (50GHz).

radiation mechanism. In order to reduce this obstruction and to measure the antenna's scattering parameters and radiation patterns adequately, it is necessary to elongate the antenna as show in Fig. 10b. To back up the advocating of this elongation, we exploited the facts that the co planar waveguide has negligible radiation, low-loss and constant effective dielectric constant in rather wide range of application from DC to above 50GHz. we decided to elongate the CPW feed *L*F to 40mm, and carried out numerical simulations of the same SWB radiators with short and long feed. The magnitudes of the reflection coefficient are compared and plotted in Fig.10c. As expected, the numerical results exposed a negligible differences as theoretically has predicted (Simons, 2001, p.240). Note that these theoretical properties (negligible radiation

and low-loss) were also experimentally consolidated by (Tanyer et al, op cit.).

**Figure 10.** Conceptual demonstration for advocating of CPW feed elongation, a) radiator with SMA connector, b) radiators with short and elongated feed, b) simulated reflection coefficient magnitudes of

The prototype 4 is measured with the Agilent E8364B PNA vector network analyzer, the electronic calibration kit N4693A 2-port ECal-module was used for full-range calibration of

The reflection coefficient magnitude of prototype 4 is measured and shown in fig. 11, the measurement agreed well with predicted value. Small deviation as frequency higher than 26 The far field radiation patterns are measured in the Delft University Chamber for Antenna Test (DUCAT); the anechoic chamber DUCAT (Fig.12a) is fully screened, its walls, floor and ceiling are shielded with quality copper plate of 0.4 mm thick. All these aimed to create a Faraday cage of internal dimension of 6 x 3.5 x 3.5 m3, which will prevent any external signal from entering the chamber and interfering with the measurements. The shielding of the chamber is for frequencies above 2 GHz up to 18 GHz at least 120 dB all around (Ligthart, 2006). All sides are covered with Pressey PFT-18 and PFT-6 absorbers for the small walls and long walls, respectively. It is found that one side reflects less than -36 dB. All these measures were taken together in order to provide sufficient shielding from other radiation coming from high power marine radars in the nearby areas.

TX: Single polarization standard horn is used as transmitter, which can rotate in yaw-ydirection to provide V, H polarizations and all possible slant polarizations. The choice of the single polarization horn above the dual polarization one as calibrator is two-folds: 1) keeps the unwanted cross-polarization to the lowest possible level, 2) and also voids the phase center interference and keeps the phase center deviation to the lowest level.

RX: Prototype 4 is put as antenna under test (AUT) on the roll-z-rotatable column (Fig.8b). For the measurements of polarimetric components (VV, HV, VH, HH, the first letter denotes

transmission's polarization state, the second is for the reception), two measurement setups are configured, the 1st is the vertical reception setup (VRS, Fig.12c) for VV, VH and the 2nd is the horizontal reception setup (HRS, Fig.12d) for HH, HV. Combination of the two setups and the TX's two polarizations provide full polarimetric patterns of the AUT.

Architecture and Design Procedure of a Generic SWB Antenna with Superb Performances for Tactical Commands and Ubiquitous Communications 177

The HV cx-polar patterns are obtained with the VRS configuration in which TX-polarization in Fig.12a is 900-rotated. Plotted in Fig.14 are the HV cx-polar patterns. As expected, perfect symmetrical and repeatable patterns can be observed in full-calibrated range (1-26GHz).

Fig.14b showed the measured HV cx-polar patterns for the in-band range (7-15GHz, 1GHz increment). The patterns consolidated the repeatable symmetrical receiving/transmitting mechanism of the prototype 4. Also observed is that all EIRP are less than -65dBm, this revealed that a greater than -20dBm XPD is obtained. Note, in the yoz−plane, theoretically no cx-polar components are expected as all cross polar components cancel each other in the 00—1800 and -900—900 direction. In a real case scenario, some cx-polar components are

**Figure 14.** HV cx-polar measured patterns; RX: VRS; TX: azimuthally oriented; a) 2D full-band patterns;

(a) (b)

The co-polar (HH) and cx-polar (VH) radiation patterns can be acquired by the HRS with two polarization states of the TX, respectively. However, due to the mounting of the antenna (shown in Fig.12d) it was not possible to measure the backside of the antenna, thus only half of the co-polar and cx-polar patterns were measured. Owing to the frequency limitations of used components (cables, adapters, connectors, absorbents), the DUCAT anechoic chamber specifications (Ligthart, 2006, op. cit.) and the desired band the in-band range is chosen from

Fig.15a showed the measured co-polar HH in-band radiation patterns. The patterns are symmetrical and repeatable with all EIRP less than -42dBm. The measured in-band cx-polar patterns for the VH configuration are plotted in Fig.15b, all peak powers have the EIRP in the order of -60dBm. The XPD of between HH and VH of the HRS displays the same

observed, their level being, nonetheless, extremely low (~ -90dBm)

*6.2.3. Co-polarized HH and Cx-polarized VH rradiation patterns* 

discrimination dynamic as that of VV and HV of the VRS.

*6.2.2. Cx-polar HV radiation patterns* 

b) Frequency parameterized 1D polar patterns

7-15GHz.

**Figure 12.** Patterns measurement set up: a) anechoic chamber DUCAT, b) AUT on the rotatable column, c) Vertical configuration and d) Horizontal configuration.

Calibration: the HF-ranges of the Sucoflex-cable, T-adapters and connectors used in this measurement set up all cataloged as 18GHz max, owing to this limitation, we calibrated the PNA with Agilent N4691B cal-kit (1-26GHz).

*6.2.1. Co-polar VV radiation patterns* 

**Figure 13.** Full-band VV co-polar measured patterns; RX: VRS; TX: zenithally oriented; a) 2D continuous patterns; b) 1D polar patterns with frequency paramaterization

#### *6.2.2. Cx-polar HV radiation patterns*

176 Ultra Wideband – Current Status and Future Trends

transmission's polarization state, the second is for the reception), two measurement setups are configured, the 1st is the vertical reception setup (VRS, Fig.12c) for VV, VH and the 2nd is the horizontal reception setup (HRS, Fig.12d) for HH, HV. Combination of the two setups

and the TX's two polarizations provide full polarimetric patterns of the AUT.

**Figure 12.** Patterns measurement set up: a) anechoic chamber DUCAT, b) AUT on the rotatable

**Figure 13.** Full-band VV co-polar measured patterns; RX: VRS; TX: zenithally oriented; a) 2D

(a) (b)

continuous patterns; b) 1D polar patterns with frequency paramaterization

Calibration: the HF-ranges of the Sucoflex-cable, T-adapters and connectors used in this measurement set up all cataloged as 18GHz max, owing to this limitation, we calibrated the

column, c) Vertical configuration and d) Horizontal configuration.

PNA with Agilent N4691B cal-kit (1-26GHz).

*6.2.1. Co-polar VV radiation patterns* 

The HV cx-polar patterns are obtained with the VRS configuration in which TX-polarization in Fig.12a is 900-rotated. Plotted in Fig.14 are the HV cx-polar patterns. As expected, perfect symmetrical and repeatable patterns can be observed in full-calibrated range (1-26GHz).

Fig.14b showed the measured HV cx-polar patterns for the in-band range (7-15GHz, 1GHz increment). The patterns consolidated the repeatable symmetrical receiving/transmitting mechanism of the prototype 4. Also observed is that all EIRP are less than -65dBm, this revealed that a greater than -20dBm XPD is obtained. Note, in the yoz−plane, theoretically no cx-polar components are expected as all cross polar components cancel each other in the 00—1800 and -900—900 direction. In a real case scenario, some cx-polar components are observed, their level being, nonetheless, extremely low (~ -90dBm)

**Figure 14.** HV cx-polar measured patterns; RX: VRS; TX: azimuthally oriented; a) 2D full-band patterns; b) Frequency parameterized 1D polar patterns

#### *6.2.3. Co-polarized HH and Cx-polarized VH rradiation patterns*

The co-polar (HH) and cx-polar (VH) radiation patterns can be acquired by the HRS with two polarization states of the TX, respectively. However, due to the mounting of the antenna (shown in Fig.12d) it was not possible to measure the backside of the antenna, thus only half of the co-polar and cx-polar patterns were measured. Owing to the frequency limitations of used components (cables, adapters, connectors, absorbents), the DUCAT anechoic chamber specifications (Ligthart, 2006, op. cit.) and the desired band the in-band range is chosen from 7-15GHz.

Fig.15a showed the measured co-polar HH in-band radiation patterns. The patterns are symmetrical and repeatable with all EIRP less than -42dBm. The measured in-band cx-polar patterns for the VH configuration are plotted in Fig.15b, all peak powers have the EIRP in the order of -60dBm. The XPD of between HH and VH of the HRS displays the same discrimination dynamic as that of VV and HV of the VRS.

Architecture and Design Procedure of a Generic SWB Antenna with Superb Performances for Tactical Commands and Ubiquitous Communications 179

**Pulse spreading and deformation**: Fig.17a shows the time-synchronization between the calculated transmit pulse (CTS) and the measured receive pulse (MRP) ( for comparison, the CTS has been normalized, time-shifted and compared with the MRP), qualitative inspection shows that the synchronization-timing between transmitted and received pulses is very good, there is no pulse spreading took place, these measured features proved that the device is suitable for accurate ranging/sensing-applications, the small deviation at the beginning of the received pulse is due to RF-leakage (Agilent, AN1287-12, p.38), and at the end of the received pulse are from environments and late-time returns (Agilent, ibid., p.38), Note that the measurements are carried out in true EM-polluted environment as shows in fig.16, and

**Figure 17.** Co-polar transmission results of VRS-configuration; a) face-to-face: calculated vs. measured;

(a) (b)

**Omni-radiation characteristics**: To correctly evaluate the omni-directional property of the AUT, both quantitative characteristics (spatial) and qualitative characteristics (temporal) are carried out, the spatial-properties of prototype 4 are already tested and evaluated in frequency-domain (as depicted in fig.13), and only the temporal-characteristic is left to be evaluated. To evaluated temporal-omni-radiation characteristics, three principal cuts are sufficiently represent the temporal-omni-radiation characteristics of the AUT in the time domain. Due to the editorial limitation, we report here only the most representative case (omni-directional in the azimuthal plane, i.e. co-polar VRS, which represents the most of all realistic reception scenarios). Fig.17b shows three MRPs of the measurement configuration pictured in Fig.16 with RX 00, 450, and 900 rotated. The results show a perfectly identical in timing, there is no time–deviation or spreading detected between the three cases. Furthermore, although the radiator is planar, it still exhibits a remarkable azimuthindependent property of 3D-symmetric radiators (for the 900 configuration, the projection of the receiving aperture vanished, however the prototype still able to receive 90% power as compare to the face-to-face case), this TD-measured results pertained the omni-directional property of the radiator, and this is also in agreement with, and as well consolidate the

b) oblique facing: measured results with RX 0-, 45- and 90-degree rotated.

validity of the measured results carried out in the FD.

*6.3.1. Pulse measurements* 

no gating applied.

**Figure 15.** In-band measured patterns; a) HH co-polarized with RX: HRS and TX: azimuthally oriented; b) VH Cx-polarized with RX: VRS and TX: azimuthally oriented.

#### **6.3. Time domain measurements**

Fig.16 shows the time domain set up for measurement and evaluation of: 1) pulse deformation, 2) the omni-radiation characteristics of the AUT. The same prototype 4 are used for TX (left) and RX (right), they stand on a horizontal foam bar which situated 1.20m above the floor.

**Figure 16.** Time domain measurement setups, equipment: Agilent VNA E8364B; Calibration kit: Agilent N4691B, calibrated method: 2-port 3.5 mm, TRL (SOLT), 300 KHz – 26 GHz

#### *6.3.1. Pulse measurements*

178 Ultra Wideband – Current Status and Future Trends

**Figure 15.** In-band measured patterns; a) HH co-polarized with RX: HRS and TX: azimuthally oriented;

(a) (b)

Fig.16 shows the time domain set up for measurement and evaluation of: 1) pulse deformation, 2) the omni-radiation characteristics of the AUT. The same prototype 4 are used for TX (left) and RX (right), they stand on a horizontal foam bar which situated 1.20m

**Figure 16.** Time domain measurement setups, equipment: Agilent VNA E8364B; Calibration kit:

Agilent N4691B, calibrated method: 2-port 3.5 mm, TRL (SOLT), 300 KHz – 26 GHz

b) VH Cx-polarized with RX: VRS and TX: azimuthally oriented.

**6.3. Time domain measurements** 

above the floor.

**Pulse spreading and deformation**: Fig.17a shows the time-synchronization between the calculated transmit pulse (CTS) and the measured receive pulse (MRP) ( for comparison, the CTS has been normalized, time-shifted and compared with the MRP), qualitative inspection shows that the synchronization-timing between transmitted and received pulses is very good, there is no pulse spreading took place, these measured features proved that the device is suitable for accurate ranging/sensing-applications, the small deviation at the beginning of the received pulse is due to RF-leakage (Agilent, AN1287-12, p.38), and at the end of the received pulse are from environments and late-time returns (Agilent, ibid., p.38), Note that the measurements are carried out in true EM-polluted environment as shows in fig.16, and no gating applied.

**Figure 17.** Co-polar transmission results of VRS-configuration; a) face-to-face: calculated vs. measured; b) oblique facing: measured results with RX 0-, 45- and 90-degree rotated.

**Omni-radiation characteristics**: To correctly evaluate the omni-directional property of the AUT, both quantitative characteristics (spatial) and qualitative characteristics (temporal) are carried out, the spatial-properties of prototype 4 are already tested and evaluated in frequency-domain (as depicted in fig.13), and only the temporal-characteristic is left to be evaluated. To evaluated temporal-omni-radiation characteristics, three principal cuts are sufficiently represent the temporal-omni-radiation characteristics of the AUT in the time domain. Due to the editorial limitation, we report here only the most representative case (omni-directional in the azimuthal plane, i.e. co-polar VRS, which represents the most of all realistic reception scenarios). Fig.17b shows three MRPs of the measurement configuration pictured in Fig.16 with RX 00, 450, and 900 rotated. The results show a perfectly identical in timing, there is no time–deviation or spreading detected between the three cases. Furthermore, although the radiator is planar, it still exhibits a remarkable azimuthindependent property of 3D-symmetric radiators (for the 900 configuration, the projection of the receiving aperture vanished, however the prototype still able to receive 90% power as compare to the face-to-face case), this TD-measured results pertained the omni-directional property of the radiator, and this is also in agreement with, and as well consolidate the validity of the measured results carried out in the FD.

#### *6.3.2. Transmission amplitude dispersion*

To evaluate the amplitude spectral dispersion of the prototype 4, the measured time-domain transmission scattering coefficients of the three co-polar configurations (00, 450, and 900 configurations displayed in fig.16) were Fourier-transformed in to frequency domain. The measured magnitudes are plotted in fig.18a, the measured results show a smooth and flat amplitude distribution in the designated band, and all are lower than -42dBm.

Architecture and Design Procedure of a Generic SWB Antenna with Superb Performances for Tactical Commands and Ubiquitous Communications 181

The intent message of this report focusses on the concept, the design methodology and the

Distinct concepts and definitions are defused and corrected. An SWB-antenna topology with simplest structure is proposed. The single layer topology paved the way for the creating of the obtained SWB antenna architecture. The antenna architecture supported, in turn, the FSD. The introduced design methodology and conceptual concept are consolidated by the

The antenna architecture provides powerful isolated-parameters to control the antenna characteristics, such as resonance-shifting, resonance matching, bandwidth broadening,

The FSD approach is introduced to obtain the required performance, whilst keeping the overall dimension of the radiator fixed, the separated sections provide engineering insights,

Parameter order and SVO methodology are elaborated in details, the priority and role of separable parameters are identified, and so, instead of multivariable-optimization, the optimization process can be accelerated by carry out sequence of SVOs. The proposed design, optimization procedure can possibly be used as a gauging-process for designing or

Although the prototype 4 comprised a simplest structure and shape, however superior SWB

This structure, although, can be modified to obtain huge frequency bandwidth, but cannot be one-size-fit-all for gain-size requirement. However, the architecture is flexible enough for

SWB prototype is designed, fabricated and evaluated for the super wideband impasse, and

Performances of the prototype are tested and evaluated. Good agreements between

Due to editorial limits, we exclusively report here only the design methodology and conceptual approach; detailed mathematical formulation and numerical aspects related to

impedance bandwidth is obtained and stable SWB-patterns are uniquely preserved.

could possibly be used as an alternative radiator for the sub-millimeter-wave regime.

scaling up/down its dimensions to match customer's gain-size requirement.

pragmatic simplification of MVO process in to a SVO one.

diffraction reduction, and SWB pattern maintaining.

and can be designed or optimized almost independently.

numerical predictions and measurements are obtained.

this SWB prototype will be published in another occurrence.

D. Tran, N. Haider, S. E. Valavan, O. Yarovyi and L. P. Ligthart

*International Research Centre for Telecommunication and Radar(IRCTR), Netherlands* 

*Laboratory of Applied Mathematics, Delft University of Technology, Netherlands* 

**7. Conclusions** 

developed prototypes.

optimizing similar SWB structures.

**Author details** 

I. E. Lager

#### *6.3.3. Transmission phase delay and group delay*

The measured phase responses of the transmission parameter for the three co-polar configurations are plotted in Fig.18b. In narrowband technology, the phase delay defined as τP =– ө/ω, is a metric for judging the quality of the transmission is the phase delay between the input and output signals of the system at a given frequency. In wideband technology, however, group delay is a more precise and useful measure of phase linearity of the phase response (Chen, 2007). The transmission group delays for the three above-mentioned configurations are plotted in Fig.18c. The plots show an excellent and negligible group delays in the order of sub-nanosecond, this is no surprise because the phase responses of the prototype are almost linear (fig.18b), thus the group delay, which is defined as the slope of the phase with respect to frequency τG =– dө/dω, resulted accordingly. Note: although the group delay (fig.18c) is mathematically defined as a constituent directly related to the phase, but it was impossible to visually observe directly from the phase plot (fig.18b), but well from the magnitude plot (fig.18a).

**Figure 18.** Measured in-band transmission coefficients a) magnitude, b) phase, c) group delay.
