**Before the**

**Federal Communications Commission**

**Washington, D.C. 20554**

+----------------------------------+----+------------------------------+
| In the matter of                 | *  | FCC Identifier               |
|                                  | *) | NUF-200SGT-0702              |
| Application for Review of        | ** |                              |
| Certification of a               |    |                              |
|                                  | *  |                              |
| Time Domain UWB Transmitter      | *) |                              |
|                                  | ** |                              |
|                                  |    |                              |
|                                  | *  |                              |
|                                  | *) |                              |
|                                  | ** |                              |
|                                  |    |                              |
|                                  | *  |                              |
|                                  | *) |                              |
|                                  | ** |                              |
+----------------------------------+----+------------------------------+

**Memorandum Opinion and Order**

**Adopted: February 10, 2003 Released: February 13, 2003**

By the Commission:

**I. INTRODUCTION**

1.  On October 11, 2002, the Commission's Office of Engineering and
    Technology (OET) issued a grant of equipment authorization to Time
    Domain Corporation ("Time Domain") for an ultra-wideband ("UWB")
    transmitter, the Signal Generator/Tag (SG/T).[^1] This device is a
    transmit-only radio to be used by UWB application developers to
    evaluate UWB propagation and co-existence with other RF devices.
    When paired with a receiver, it can also be configured to pass data
    packets that support UWB ranging and positioning, and
    communications.[^2]

2.  This grant of equipment authorization was challenged by a coalition
    of companies and associations ("Petitioners"). [^3] The Petitioners
    request that the Commission review and reverse the grant of Time
    Domain's equipment authorization because of alleged non-compliance
    with specific UWB limits contained in the FCC Rules. For the reasons
    stated below, we deny the Petitioners' application for review.

**II. BACKGROUND**

3.  On February 14, 2002, the Commission adopted new regulations to
    permit the operation of UWB transmitters on an unlicensed basis
    under Part 15 of its rules.[^4] Several categories of UWB devices
    were established with different standards for these devices based on
    their individual operating characteristics and potential for causing
    interference to the authorized radio services. The emission limits
    for UWB devices are more stringent than for other unlicensed devices
    at frequencies below 3.1 GHz, particularly in the 0.96 to1.61 GHz
    frequency band used by GPS and other Aeronautical Radionavigation
    Services. In adopting the standards for UWB devices, the Commission
    noted that many UWB transmission systems will incorporate digital
    circuitry which also will radiate RF emissions. It also noted that
    requiring the emissions from this associated digital circuitry to
    comply with some of the reduced levels adopted for UWB devices may
    make production infeasible. Accordingly, the Commission adopted
    rules to permit the emissions from digital circuitry used to enable
    operation of an UWB device to operate at the Part 15 general
    emission limits in 47 C.F.R. § 15.209 provided that it can be
    clearly demonstrated that those emissions are due solely to
    emissions from the digital circuitry and are not intended to be
    radiated from the UWB device's antenna.[^5]

**III. DISCUSSION**

4.  The Petitioners claim that the emissions below 3.1 GHz from the Time
    Domain transmitter exceed the limits permitted under the
    regulations.[^6] The petitioners contend that only digital circuitry
    used for the internal operation of the transmitter, such as digital
    clocks or other housekeeping functions, are permitted to operate at
    the higher limits in 47 C.F.R. § 15.209.[^7] They argue that the way
    to determine what emissions are from digital circuitry is to remove
    or to disable all components and software associated with the UWB
    transmitter.[^8] The Petitioners also claim that there is a defect
    in the Time Domain certification application because it does not
    contain data on the filter characteristics or the measured level of
    emissions below 3.1 GHz.[^9] The Petitioners add that the Commission
    should require applicants to demonstrate that unintended emissions
    below 3.1 GHz are from the microprocessor and are completely
    uncorrelated with the intended transmit signal, existing only when
    all circuitry and software associated with the transmitter have been
    removed.[^10]

5.  In its November 11, 2002 response to the application for review,
    Time Domain notes that the subject transmitter consists of a digital
    module and an RF module.[^11] The digital module is used to
    facilitate the connection of the device to a computer as well as to
    enable the generation of the UWB signal by the RF module. Time
    Domain states that its transmitter fully complies with the
    applicable standards and that its application for certification
    correctly stated that there were no intentional emissions between
    960 MHz and 3100 MHz.[^12] Time Domain asserts that the UWB rules
    require that signals emitted from the antenna of its transmitter
    comply with the UWB emission requirements specified in our rules (47
    C.F.R. § 15.517) while signals from digital circuits in the device
    must comply with the general emissions limits in our rules (47
    C.F.R. § 15.209).[^13]

6.  Reply comments were filed by Sprint Corporation and by the
    petitioners. Sprint argues that the emissions from the Time Domain
    transmitter are not necessarily emissions from digital circuitry nor
    are they necessarily not intended to be radiated from the
    antenna.[^14] Sprint believes that Time Domain has not clearly
    demonstrated that the emissions below 3.1 GHz from its transmitter
    are due to emissions from digital circuitry. The Petitioners
    reiterate their earlier arguments that Time Domain's assertions of
    compliance are not supported by test data, adding that the
    Commission's rules require a report of the emission levels in the
    960 MHz to 3100 MHz band.[^15] The Petitioners believe that
    components of the transmitter should not be categorized as digital
    circuitry and that the emissions from these components should not be
    subject only to the less stringent Part 15 general emission
    limits.[^16] They also argue that testing for unintentional
    emissions with the antenna connection terminated is inconsistent
    with the Commission's regulations for intentional radiators, and
    that unintentional emission testing must be performed with the
    transmitter in a quiescent state with no radio frequency or
    associated devices active.[^17] The petitioners add that allowing
    higher emissions from digital circuitry associated with the
    transmitter undermines the conservative approach taken by the
    Commission for protecting other radio operations.[^18]

7.  OET's review of the application for certification from Time Domain
    for its UWB transmitter found that the transmitter complies with all
    of the limits in the Commission's rules. Such transmitters are
    required to confine their 10 dB bandwidth between 3.1 and 10.6 GHz
    and are subject to reduced emission levels between 960 and 3100 MHz.
    As pointed out by the petitioners, Time Domain's application for
    equipment authorization did not contain data on measured emissions
    in the 960 to 3100 MHz frequency range. However, this omission does
    not render the application defective. The FCC's rules require that
    an application for certification include a report of measurements
    demonstrating compliance as determined by following the test
    procedures of the American National Standards Institute (ANSI)
    C63.4‑1992.[^19] According to Section 10.1.8.2 of ANSI C63.4, only
    the fundamental and three spurious emissions are required to be
    reported to the Commission. Lacking any other procedures or guidance
    from the Commission, Time Domain was not required to report any of
    the emissions detected in the 960 to 3100 MHz band in its
    application for certification.

8.  Also, as discussed above, the regulations specifically permit
    emissions to comply with the Part 15 general emission limits in 47
    C.F.R. § 15.209, rather than the limits specified in 47 C.F.R. §
    15.517, if they are from associated digital circuitry used to enable
    the operation of the UWB device.[^20] In conjunction with the
    approval process, OET staff independently tested the Time Domain
    equipment and confirmed that the emissions appearing in the 960 MHz
    to 3100 MHz band were produced by associated digital circuitry and
    were not intended to be emitted by the transmitter's antenna.
    Accordingly, these emissions are subject to the Part 15 general
    emission limits specified in 47 C.F.R. § 15.209 and not to the more
    stringent limits in 47 C.F.R. § 15.517(c).

9.  Because the Time Domain device was the first non-ground penetrating
    radar unit submitted for equipment authorization under the new UWB
    rules, and because it offered OET staff engineers the first
    opportunity to further develop standardized UWB compliance
    measurement procedures, a complete RF characterization was performed
    on this device. The results of that testing, contained in the
    attached Appendix, demonstrate conclusively that the Time Domain
    transmitter complies with all of the relevant FCC rules for UWB
    equipment. Although some narrow band emissions were detected in the
    960-3100 MHz band, these emissions are attributable to the
    associated digital circuitry contained within the UWB device, are
    not radiated by the UWB antenna, and are compliant with the Part 15
    general emission limits in 47 C.F.R. § 15.209, as stipulated under
    47 C.F.R. § 15.521(c). Our investigation identified the narrowband
    emissions in the 960 to 3100 MHz band as harmonics of the 19.2 MHz
    oscillator contained in the digital module portion of Time Domain's
    UWB device. To confirm that the emissions in the 960 to 3100 MHz
    band are not intended to be radiated by the device's antenna, the
    emissions levels were measured with the antenna removed and its
    connection port terminated. As can be seen from the OET report,
    under this configuration the UWB emissions were no longer present;
    however, the narrow band emissions were still observed. This
    indicates that the narrow band emissions do not radiate from the
    device's antenna. For further confirmation, a spectrum analyzer was
    attached to the UWB antenna port to measure the conducted emissions
    from the Time Domain transmitter. As shown in the attached report,
    under this test condition no narrow band emissions were observed
    between 960 and 3100 MHz. We reject the arguments of the petitioners
    that it is necessary to remove or disable all components or software
    associated with the UWB transmitter to determine if the emissions
    are generated by the digital circuitry. Such a requirement would
    necessitate disassembly and re-engineering of the device in order to
    perform the tests. This requirement is not feasible. Further, the
    emissions from digital circuitry associated with the transmitter are
    included under the provisions in 47 C.F.R. § 15.521(c). Requiring
    the removal of this circuitry would not provide useful test results.

10. As demonstrated above, the narrowband emissions produced in the 960
    to 3100 MHz band by Time Domain's SG/T UWB device are subject to the
    Part 15 general emission limits contained in 47 C.F.R. § 15.209. We
    disagree with the claims by the petitioners that digital components
    used to control the transmitter are subject to the more stringent
    limits associated with the transmitter. It is clear that the digital
    circuitry discussed in 47 C.F.R. § 15.521(c) includes circuitry used
    to control and enable the operation of the transmitter, *e.g.*,
    digital circuitry used to trigger the pulse output of the
    transmitter. It also is clear that 47 C.F.R. § 15.521(c) permits the
    emissions from this digital circuitry to be radiated at the Part 15
    general emission levels specified in 47 C.F.R. § 15.209.

    **IV. ORDERING CLAUSES**

11. Accordingly, IT IS ORDERED that the Application for Review of the
    grant of certification issued to the UWB transmitter from Time
    Domain Corporation, FCC ID NUF-200SGT-0702, IS DENIED. This action
    is taken pursuant to Sections 302, 303(e), and 303(f) of the
    Communications Act of 1934, as amended, 47 U.S.C. 302, 303(e), and
    303(f).

12. For further information regarding this Memorandum Opinion and Order,
    contact John A. Reed, Office of Engineering and Technology, (202)
    418-2455, <jreed@fcc.gov>.

FEDERAL COMMUNICATIONS COMMISSION

Marlene H. Dortch

Secretary

**APPENDIX**

**RADIATED EMISSIONS CHARACTERIZATION OF**

**TIME DOMAIN CORPORATION'S**

**SIGNAL GENERATOR/TAG (SG/TAG)**

**ULTRA-WIDEBAND (UWB) TRANSMITTER**

Federal Communications Commission

Office of Engineering and Technology/Laboratory Division

23 January 2003

**1.0 INTRODUCTION**

On February 14^th^, 2002, the Federal Communications Commission (FCC)
adopted the *First Report and Order* ("*R&O*") authorizing the limited
use of Ultra-Wideband (UWB) devices on an unlicensed basis under Part 15
of the FCC rules.[^21] The FCC Office of Engineering and Technology
(OET), through its Equipment Authorization Branch (EAB), granted the
first Equipment Authorization (FCC ID: NUF-200SGT-0702) for an
indoor-operating UWB transmitting device on October 11, 2002.

The application for authorization was filed with the EAB on July 29^th^,
2002. The application was submitted with a companion test report,
documenting the results of compliance testing performed by an
independent accredited test laboratory.[^22] A sample of the UWB device
described in the application was also provided to EAB.

Since this was the first application submitted under the new rules for
indoor UWB transmitters, and because it offered OET staff engineers a
first opportunity to further develop standardized UWB compliance
measurement procedures, a complete radio frequency (RF) radiated
emissions characterization was performed on this device. The data
collected from these measurements was considered in conjunction with
that provided by the applicant to determine compliance to the applicable
rules.[^23]

Several parties have since raised questions regarding the granting of
this authorization.[^24] They have expressed concerns that the device
intentionally emits RF signals into the 960-3100 MHz frequency band at
amplitudes that are in excess of the UWB emissions limits applicable to
this frequency range.

This report documents and explains the pertinent data extracted from the
FCC evaluation of the subject device. The data contained herein is a
subset of the complete data set collected; however, it is adequate to
address the concerns expressed within the Application for Review.

**2.0 DEVICE DESCRIPTION**

The UWB device for which the Equipment Authorization was granted is a
Signal Generator/TAG ("SG/TAG") Model Number 100-0011C, Serial Number
TGHC00103, designed and manufactured by Time Domain Corporation. This
device is a transmit-only radio to be used by UWB application developers
to evaluate UWB propagation and co-existence with other RF devices. When
paired with a receiver, it can also be configured to pass data packets
that support UWB ranging, positioning and communications.

The SG/TAG applies a nominal 500 pico-second pulse to the transmitting
antenna at a non-adjustable pulse rate of 10 million pulses per second
(10 MHz). The device is powered from 120 volt, 60 Hz AC power and is
fitted with a non-removable power cord.

The application for authorization was submitted under CFR 47 Part 15,
Subpart F, Section 15.517, "*Technical requirements for indoor UWB
systems*," which is the applicable section of the UWB rules.

**3.0 MEASUREMENT DETAILS**

**3.1 Measurement System**.

The components used in performing these measurements are listed in Table
1, along with pertinent specifications. A block diagram showing the
measurement equipment configuration used in the subsequent compliance
tests is provided in Figure 1.

Table 1. List of Measurement Equipment.

+----------------+---------------+------------+----------+------------+
| *              | **M           | **MODEL**  | **       | *          |
| *DESCRIPTION** | ANUFACTURER** |            | SERIAL** | *FREQUENCY |
|                |               |            |          | RANGE      |
|                |               |            | **       | (GHz)**    |
|                |               |            | NUMBER** |            |
+----------------+---------------+------------+----------+------------+
| PSA Spectrum   | Agilent       | E4448A     | US       | 0.0        |
| Analyzer       |               |            | 42070179 | 00003-50.0 |
+----------------+---------------+------------+----------+------------+
| Swept CW       | Agilent       | 83650L     | 38       | 0.01-50.0  |
| Signal         |               |            | 44A00650 |            |
| Generator      |               |            |          |            |
+----------------+---------------+------------+----------+------------+
| Low Noise      | He            | HP83017A   | 36       | 0.5-26.5   |
| Pre-Amp        | wlett-Packard |            | 11A01199 |            |
+----------------+---------------+------------+----------+------------+
| Low Noise      | Miteq         | AF         | 856403   | 1.0-2.0    |
| Pre-Amp        |               | S3-0100020 |          |            |
|                |               | 0-06-10P-6 |          |            |
+----------------+---------------+------------+----------+------------+
| Double Ridge   | A.H. Systems, | S          | 387      | 0.7-18.0   |
| Guide Horn     | Inc.          | AS-200/571 |          |            |
| Antenna        |               |            |          |            |
+----------------+---------------+------------+----------+------------+
| Coaxial Cable  | Times Wire    | LMR-400    | \-       | \< 16.2    |
|                | and Cable     |            |          |            |
+----------------+---------------+------------+----------+------------+

![](media/image1.png){width="6.0in" height="2.486111111111111in"}

Figure 1. Block Diagram of Measurement System.

The PSA spectrum analyzer incorporates a true root-mean-square (RMS)
detector and was used to perform all radiated emissions measurements
above 960 MHz. The specific analyzer settings are provided in the
subsequent sections describing the tests performed.

A very low-noise, octave-tuned (1-2 GHz), pre-amplifier was used to
implement the LNA shown in the block diagram to facilitate the radiated
emissions measurements within the 960-1610 MHz frequency range, where
the UWB emission limits are extremely stringent. This configuration is
necessary to reduce the measurement system operational sensitivity in
order to detect radiated emissions from the device under test (DUT) at
the extremely low amplitude levels defined by the emissions limit in
this frequency band. A broadband (0.5-26.5 GHz) pre-amplifier was used
to implement the LNA for the measurements performed in the 1610-3100 MHz
frequency range. At each data point considered in these tests, the
calibrated signal generator was used to determine the measurement system
characteristics at the associated frequency.

A double ridge-guide broadband horn antenna was used to receive the
radiated emissions within the 960‑3100 MHz band. The antenna
characteristics were determined from manufacturer-supplied calibration
data.

All radiated tests utilized a one-meter separation distance between the
DUT and the measurement antenna. This enabled an improved
signal-to-noise ratio (S/N) for the radiated tests. Although these types
of measurements are typically performed at a distance of three-meters,
it was necessary to reduce the measurement distance to enable
discrimination between the emissions radiating from the DUT and the
measurement system noise floor.

**3.2 Measurement Facility**

These measurements were performed at the FCC Laboratory, located on
Oakland Mills Road, in Columbia, Maryland. The geographic coordinates of
the laboratory are 39º10.093'N latitude and 076º49.706'W longitude.

The measurements were performed in the pre-compliance laboratory within
the main facility. This room consists of two walls constructed of
painted cinder block and two walls constructed of painted metal siding.
The floor is covered with conventional ceramic tile and measures
approximately 30 by 30 feet. The ceiling is a drop ceiling constructed
of 2-feet by 4-feet acoustical tile panels at a height of approximately
18 feet above the floor. No effort was made to characterize the room in
terms of reflective or resonant RF properties.

The room is not shielded from RF energy and thus is subject to the
presence of ambient signals. For these measurements, the known ambient
signals of concern include cellular telephone signals in the 800 MHz
band, paging system signals in the 900 MHz band, Air Traffic Control
Radio Beacon signals at 1030 and 1090 MHz, and PCS signals in the 1.9
GHz band. Although the cellular and paging system signals are located
outside of the frequency bands examined herein, it was necessary to
determine their presence and amplitude in order to assess the potential
for high-power effects to the pre-amplifiers utilized in the measurement
system. Measurements were performed that eliminated this factor as a
cause for concern and thus, the use of pre-select filtering was
determined not to be required for these tests.

**3.3 Data Reduction Techniques**

The data reduction performed herein is presented in terms of power
spectral density (PSD). The UWB emission limits are expressed in terms
of equivalent isotropic radiated power (EIRP). The PSD levels detected
at the measurement antenna were related to an EIRP for comparison to the
applicable emissions limits through application of the basic free-space
propagation loss equation.

**4.0 PEAK SPECTRAL ENVELOPE MEASUREMENT**

The DUT was placed in the center of a non-conducting turntable. The
measurement antenna was placed at a distance of 1-meter from the DUT.
Both the resolution bandwidth (RBW) and the video bandwidth (VBW) of the
analyzer were set to 3 MHz. The sweep time was automatically selected by
the analyzer based on the frequency span of the measurement. The
spectrum analyzer's positive peak detector was used in maximum-hold mode
to capture and retain the peak power detected within each measurement
bin.

A background measurement was first performed with the DUT turned off to
detect any ambient signals present within the measurement area. This was
necessary to enable discrimination between the emissions radiated by the
DUT and any existing ambient emissions present in the measurement area.
The DUT was then turned on and continuously rotated while the
measurement antenna was stepped in height between 1 and 4 meters and
varied between vertical and horizontal polarization. This methodology
results in a measurement of the maximum spectral envelope radiated by
the DUT.

The spectral envelope measurement revealed the fundamental UWB emission,
as defined by the outermost -10 dB points, to be contained entirely
within the 3.1 to 10.6 GHz frequency band, as specified in the
applicable rules section. However, several narrow-band (*i.e.*, 3 dB
bandwidth \< 2 MHz) emissions were observed in the 960-3100 MHz band.
Each of these identified emissions was examined independently using the
techniques described below to determine the associated RMS average
amplitude levels.

**5.0 AVERAGE POWER MEASUREMENTS**

The emission limits specified in the applicable rules section are
defined in terms of RMS average EIRP in a 1 MHz measurement bandwidth.
This section describes the techniques used to measure the RMS average
emission levels for comparison to the emissions limits.

The spectrum analyzer was set to utilize both a resolution and video
bandwidth of 1 MHz. The RMS average detector was selected. The sweep
time was set to 6 milliseconds and the detected amplitude levels were
averaged over 100 consecutive sweeps. This combination resulted in a
1-millisecond integration time within each of the 601 measurement bins.

The frequency span of the analyzer was set to 10 MHz and centered to
coincide with the center frequency associated with each specific
narrow-band emission identified from the spectral envelope measurement.
A full system calibration was performed at each of these center
frequencies.

**6.0 MEASUREMENT SUMMARY**

Table 2 lists all of the DUT radiated emissions detected in the 960-3100
MHz frequency band that exceed the UWB emissions limit.

Table 2. Radiated Emissions Detected in the 960-3100 MHz Band.

+-----------+----------+-----------+-----------+-----------+-----------+
| **FR      | **AD     | **FREE    | **EIRP**  | *         | *         |
| EQUENCY** | JUSTED** | SPACE     |           | *MARGIN** | *MARGIN** |
|           |          | PATH      | **(d      |           |           |
| **(MHz)** | **RMS    | LOSS**    | Bm/MHz)** | **        | **        |
|           | PSD**    |           |           | (Relative | (Relative |
|           |          | **@ 1m**  |           | to**      | to**      |
|           | **(dB    |           |           |           |           |
|           | m/MHz)** | **(dB)**  |           | **UWB     | **15.209  |
|           |          |           |           | Limit)**  | Limit)**  |
|           |          |           |           |           |           |
|           |          |           |           | **(dB)**  | **(dB)**  |
+-----------+----------+-----------+-----------+-----------+-----------+
| 998.4     | -99.3    | 32.5      | -66.8     | 8.5       | -25.5     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1075.2    | -102.7   | 33.1      | -69.6     | 5.7       | -28.3     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1107.8    | -105.7   | 33.4      | -72.3     | 3.0       | -31.0     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1152.0    | -107.3   | 33.7      | -73.6     | 1.7       | -32.3     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1228.8    | -102.4   | 34.3      | -68.1     | 7.2       | -26.8     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1305.6    | -98.8    | 34.8      | -64.0     | 11.3      | -22.7     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1382.4    | -106.2   | 35.3      | -70.9     | 4.4       | -29.6     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1459.2    | -109.5   | 35.8      | -73.7     | 1.6       | -32.4     |
+-----------+----------+-----------+-----------+-----------+-----------+
| 1536.0    | -93.7    | 36.2      | -57.5     | 17.8      | -16.2     |
+-----------+----------+-----------+-----------+-----------+-----------+

Each of these emissions was observed to be relatively narrow band, with
a 3 dB bandwidth less than 2 MHz. Similarities were also noted between
these emissions and those which have been observed in previous FCC
studies of radiated emissions generated by digital devices.[^25]
Therefore, it was suspected that the source of these narrow band
emissions is the digital circuitry contained within the device. The
current UWB rules allow for emissions at higher levels than the limits
"*if it can be clearly demonstrated that an emission from a UWB
transmitter is due solely to emissions from digital circuitry contained
within the transmitter and that the emission is not intended to be
radiated from the transmitter's antenna,...*"[^26] In which case,
*"...the limits shown in Section 15.209 of this chapter shall apply to
that emission rather than the limits specified in this section.*"[^27]
Since this is the exception invoked in the application for
certification, a methodology was formulated to determine whether these
narrow band emissions are indeed attributable to the digital circuitry
and not intended to be radiated from the transmitter's antenna. The
details of this methodology are presented in the following section.

**7.0 METHODOLOGY FOR ISOLATING DIGITAL EMISSIONS**

The first method utilized for attempting to isolate the observed
narrow-band emissions was to disconnect the radiating antenna from the
device and terminate the antenna output port into a 50-ohm load. This
was facilitated by the fact that the DUT utilizes a removable antenna
connected via an external antenna port. A radiated measurement was
performed with the antenna port terminated. It was observed from this
measurement that the UWB emission, which is radiated from the antenna,
was no longer present; however, the narrow-band emissions were still
observed at equivalent amplitude levels. This is an indication that the
narrow-band emissions are not being radiated from the DUT antenna.

A subsequent test was performed to ascertain that the source of these
emissions is the digital circuitry within the device and not related to
the UWB emission. In this test, the output from the DUT antenna port was
applied directly to the spectrum analyzer in a conducted (*i.e*.,
non-radiated) measurement. In this test, the UWB emission is clearly
observed, but the narrow band emissions are no longer present. The
results of this test provide adequate evidence that the narrow band
emissions observed in the radiated tests are generated from internal
digital circuitry and are not radiated from the antenna.

Although the tests described above are adequate justification for
invoking the noted rule exception, an additional evaluation step was
performed based on the observation of an interesting relationship
recognized within the measurement data. A review of the data in Table 2
reveals that, with but one exception, all of the narrow-band emissions
are related by a constant value of 76.8 MHz. Upon recognition of this
relationship, the block diagram provided with the application[^28] was
examined. A 19.2 MHz oscillator is shown in the block diagram of the
Digital Module of the DUT. The 76.8 MHz relationship observed in the
measured data was determined to be an integral multiple of 19.2 MHz
(*i.e.*, 19.2 MHz x 4 = 76.8 MHz). Thus, it was deduced that the
narrow-band emissions observed in the radiated emissions testing of this
device are most likely harmonic emissions associated with this
oscillator.

The cumulative results of these tests provide compelling evidence that
the narrow-band emissions observed in the 960-3100 MHz band are indeed
generated by the digital circuitry contained within the transmitter and
thus, are subject to the emissions limits defined in Section 15.209. The
applicable emissions limit from this rules section is 500 µV/m at 3
meters, which is equivalent to an EIRP of ‑41.3 dBm/MHz. An examination
of the measured emission levels identified in Table 2, demonstrates that
each of the observed narrow-band emissions is in compliance with this
limit.

**8.0 CONCLUSIONS**

The SG/TAG Model Number 100-0011C UWB device was found to be fully
compliant with the applicable rules for the category of UWB devices
under which the application was submitted. All radiated UWB emissions
are compliant with the applicable emissions limits depicted in the
appropriate rules section. Although some narrow band emissions were
detected in the 960-3100 MHz frequency band, with levels in excess of
the UWB emissions limits, they were determined not to be radiating from
the DUT antenna and were convincingly attributed to the digital
circuitry within the device. Therefore, according to the provisions of
Section 15.521(c), these emissions are not subject to the UWB emissions
limits, but are instead subject to the emission limit defined in Section
15.209. Each of these narrow-band emissions was found to be compliant
with the applicable emissions limit.

[^1]: *See* file for FCC ID number NUF-200SGT-0702. All equipment
    authorization files and correspondence referenced herein are
    accessible electronically at: http://www.fcc.gov/oet/fccid/.

[^2]: *Id.*

[^3]: *See* Application for Review filed by the coalition
    ("Petitioners") consisting of: Air Transport Association of America,
    Inc.; American Airlines; American Congress on Surveying and Mapping;
    ARINC; AT&T Wireless Services, Inc.; The Boeing Company; Delta Air
    Lines, Inc.; Garmin International, Inc.; General Aviation
    Manufacturers Association; Multispectral Solutions, Inc.; National
    Business Aviation Association, Inc.; NavCom Technology, Inc.; Nortel
    Networks, Inc.; Northwest Airlines, Inc.; NovAtel Inc.; PanAmSat
    Corporation; QUALCOMM Incorporated; Raytheon Company; Rockwell
    Collins, Inc.; Satellite Industry Association; Sirius Satellite
    Radio Inc.; Spatial Technologies Industry Association; Sprint
    Corporation; Tendler Cellular, Inc.; Trimble Navigation Ltd.; United
    Airlines; United States GPS Industry Council; and XM Radio Inc.

[^4]: *See First Report and Order* ("*R&O*") in ET Docket No. 98-153, 17
    FCC Rcd 7435 (2002).

[^5]: *Id*. at paragraph 207.

[^6]: Petition at pg. 2-3.

[^7]: *Id.* at pg. 6-7.

[^8]: *Id.* at pg. 6.

[^9]: *Id.* at pg. 6.

[^10]: *Id.* at pg. 6.

[^11]: Time Domain comments at pg. 2

[^12]: *Id.*

[^13]: *Id.* at pg. 3. Digital devices, which can be distinguished from
    digital circuitry based on the definition in 47 C.F.R. §15.3(k), are
    subject to the limits specified in 47 C.F.R. § 15.109. Except for
    the special category of Class A digital devices, permissible
    emission levels for digital devices are the same as the general
    radiated emission levels set forth in 47 C.F.R. § 15.209.

[^14]: Sprint reply comments at pg. 3.

[^15]: Petitioners reply comments at pg. 2.

[^16]: *Id.* at pg. 4 and 6. .

[^17]: *Id.* at pg. 4.

[^18]: *Id.* at pg. 5.

[^19]: *See* 47 C.F.R. § 2.1033(b)(6) and 47 C.F.R § 15.31(a)(6).

[^20]: *See R&O*, *supra*, at para. 207 and 47 C.F.R. § 15.521(c).
    Further, emissions from associated digital devices, *e.g.*,
    emissions from digital circuitry used to control additional
    functions or capabilities other than the UWB transmission, are
    subject to the limits applicable to digital devices.

[^21]: *First Report and* Order in ET Docket No. 98-153, 17 FCC Rcd 7435
    (2002).

[^22]: Hiday, J.D., *Evaluation of the TAG Model Number: 100-0011C to
    CFR 47 Part 15, Subpart F*, Report Number: 0227351uwb.doc, Intertek
    Testing Services, Inc., ETL SEMKO, 22 July 2002, (hereinafter
    "Intertek Report").

[^23]: The testing that is the subject of this report was conducted
    prior to issuing the grant of certification to Time Domain. This
    report summarizes the procedures that were used and test data that
    was obtained.

[^24]: US GPS Industry Council, et al, *Application for Review*, 22
    October 2002.

[^25]: FCC Project TRB 02-02 Report, *Measured Emissions Data for Use in
    Evaluating the Ultra-Wideband (UWB) Emissions Limits in the
    Frequency Bands Used By the Global Positioning System (GPS)*, ET
    Docket No. 98-153, October 22, 2002.

[^26]: 47 C.F.R. § 15.521 (c).

[^27]: *Id.*

[^28]: *See* Exhibit 3, SG/TAG Functional Block Diagram.