DESIGN STUDY ON A DIRECT CONVERSION RECEIVER FRONT-END FOR
`280 MHZ, 900 MHZ, and 2.6 GHZ BAND RADIO COMMUNICATION SYSTEMS
`
`HiroshiTsurumi and Tadahiko Maeda
`
`Research and Development Center
`TOSHIBA corpofation
`1, Komukai Toshiba-cho. Saiwai-h, Kawasaki, 210, Japan
`
`Abstract
`receiver has recently been receiving
`A direct conversion
`attention as suitable architecture for use in realizing a 1-chip
`LSI receiver.
`However, in order to adopt a direct conversion receiver to
`communication terminals, it is necessary to consider that local
`oscillator radiation will interfere with nearby receivers, since
`its
`frequency
`is equal
`to
`the desired carrier
`frequency.
`Furthermore nonlinear distortion in the RF stage also should be
`considered especially
`in outdoor radio communication systems
`where multiple signals from other radio stations are transmitted.
`This paper describes the required RF stage performance for
`the direct conversion
`receiver, with
`discussions on
`the
`as mobile
`feasibility of using
`this
`architecture
`terminal
`equipment for 280 MHz, 900 MHz, and 2.6 GHz band radio
`communication systems.
`
`1. Jntroduction
`The direct conversion principle has been well known as a
`signal, under the
`demodulation method, especially for an AM
`name of ‘‘ synchrodyne”
`or “ homodyne”
`[l]. Recently, this
`its suitability for
`principle has been
`recovered because of
`realizing 1-chip
`receiver implementation[2]-[SI. The reason
`is
`that the channel selection filter can be realized by an LSI
`as gyrator
`or
`chip,
`such
`switched
`capacitor
`filters.
`image response,
`Furthermore, this receiver architecture has no
`and thus the narrowband image rejection filter in the RF stage,
`which tends to be bulky, can be removed or replaced with a
`rather more broadband one.
`However, for the use of a direct conversion receiver
`in
`practical radio communication systems, some important subjects
`exist regarding the RF stage, but little attention has been
`directed to this point.
`inherent problems for a direct
`This paper
`reports on
`conversion
`receiver. These problems
`include
`local oscillator
`(LO) radiation and nonlinearity of the RF amplifier or mixer,
`which have not been
`treated quantitatively. Specifications for
`the RF component, such as the mixer or the RF filter, were
`investigated
`the
`direct conversion
`receiver
`in
`for using
`practical radio communication systems.
`Direct conversion receivers for 280 MHz, 900 MHz, and 2.6
`GHz band radio communication systems are discussed. First, the
`radiation influence on adjacent receivers will be discussed.
`LO
`The required attenuation for LO leakage power was obtained from
`experimental results and calculations for an assumed
`radio
`communication system at the above frequency band. Next, the
`required outband attenuation for the RF filter is discussed,
`together with the result of bit error rate measurements under an
`outdoor radio wave environment on 280 MHz receiver and with
`theoretical calculations on the 900 MHz and 2.6 GHz receivers.
`
`2. Receiver Architecture and
`AssumedSystem Parameters
`the direct conversion
`The
`fundamental blockdiagram
`for
`receiver, which was investigated during this research, is shown
`in Fig. 1. The RF filter shown in Fig. 1 can be inserted
`This is discussed
`either before or after the RF amplifier.
`briefly in section 4. The input signal is amplified by the low
`noise amplifier. Then, it is down converted by the subsequent
`mixer stage and
`filtered by
`the following channel selection
`filter designed by active filters, and finally demodulated by a
`phase detector (PD).
`Table 1 shows the system parameters for the discussion in
`this paper. The 280 MHz system is assumed to be a wide-area
`paging system and the terminal performs only as a receiver. On
`the other hand, the 900 MHz and 2.6 GHz system are assumed
`to be cellular telephones equipped with transmitting as well as
`receiving functions.
`3. Lo Radiation
`radiation
`In a direct conversion receiver, undesirable LO
`will interfere with nearby
`receivers, since
`its frequency
`is
`equal to
`the desired carrier frequency. The radiation power
`must be attenuated by such means as LO-RF
`isolation of a
`In
`good balanced mixer and Si2 of a RF amplifier.
`the
`following, the required attenuation for LO
`leakage power is
`discussed.
`In this section, only LO
`leakage is assumed to be
`the interference signal.
`First, the acceptable LO
`leakage power (PI) in the direct
`conversion
`receiver
`satisfying
`the
`required
`system
`for
`is necessary
`It
`specifications is calculated.
`this purpose
`for
`to obtain acceptable interference signal power (Pr) received by
`this case, Pr is given
`a nearby direct conversion receiver.
`In
`bY 9
`
`Pr [dBm] = D [dBm] - D/I [dB]
`where D/I
`is the desired signal (D) power to the interference
`signal (I) power ratio for the required bit error rate (BER),
`in this paper 10-2. The Friis transmission
`formula can be
`adopted, since
`the distance between
`two direct conversion
`receivers (r) is assumed to be sufficiently short. Therefore, PI
`becomes
`
`(1)
`
`PI = (4m/$Pr/Gr/Gt
`
`(2)
`
`where Gt and Gr are the transmitting and receiving antenna
`the
`direct
`conversion
`receiver.
`gains
`respectively
`for
`
`(a) 280 MHz Band
`The acceptable LO
`the
`leakage power PI in Eq.(2) in
`280 MHz system
`is calculated. In a 280 MHz band system,
`frequency shift keying (FSK), widely adopted in radio paghg
`
`45 7
`
`CH2944-7/91/000010457 $1 .OO Q 1991 IEEE
`
`_ _ _ _
`
`~
`
`- - -~
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`TCL EXHIBIT 1029
`Page 1 of 6
`
`

`
`systems, is assumed for the modulation scheme. For the FSK
`direct conversion
`receiver described
`in Table 1, the relation
`in Eq. (1) and EbMO is calculated
`between the required D/I
`this result, the acceptable leakage
`and given in Fig. 2. From
`power which affects no other adjacent terminal within 1 m or 3 m
`is calculated as a function of
`the distance from
`the base
`In this calculation,
`station.
`the propagation
`characteristic
`model in Reference
`[6] is assumed. Fading and shadowing
`margins, listed in Table 1 are also take into account for the
`desired signaltransmitted from the base station.
`the
`in Fig. 3, where
`The calculation results are shown
`amptable LO leakage power P1 was approximately -60 dBm and
`-50 dBm at the edge of the service area when the distances
`to be 1 m and 3 m,
`between
`two
`terminals were assumed
`respectively. Therefore, the required attenuation for the LO
`leakage achieved by the the LO-RF isolation of the mixer and
`& of the RF amplifier became -50 dB and -40 dB, respectively,
`with regard to the assumed -10 dBm LO power listed in Table 1.
`@) 900 MHz and 2.6 GHz Band
`The acceptable LO leakage power
`the direct
`from
`the 900 MHz and 2.6 GHz
`conversion receiver tenninal in
`to the 280 MHz system.
`systems was obtained
`similar
`The 900 MHz and 2.6 GHz systems were assumed to be
`telephone systems. For
`this application, d4-QPSK
`cellular
`is adopted as the modulation scheme.
`In
`the case of a
`in Table 1, the
`n/4-QPSK direct conversion receiver d&bd
`relation between the required D/I for Eq. (1) and EblNO is shown
`in Fig 4.
`In a practical receiver, the detection of a d4-QPSK
`signal using
`the
`direct
`conversion
`principle
`is difficult
`without an automatic gain control (AGC). However, the solution
`is rather beyond the purpose of this paper, so
`for this problem
`the AGC is assumed to work perfectly.
`In the 900 MHz direct conversion receiver, the acceptable
`leakage power at the edge of the seMce area under the
`LO
`condition of the distances between two terminals being 1 m and
`3 m are approximately -90 dBm and -80 dBm, respectively, as
`shown in Fig. 5. Therefore, the required attenuation for the LO
`leakage with regard to -10 dBm LO power are -80 dB and -70
`dB, respectively.
`In the 2.6 GHz system, the service area is assumed to be a
`rather
`small cell structure, with
`a 200 m
`cell
`radius.
`Therefore, the distance between
`the base station and
`the
`receiver terminal can not satisfy the condition
`in Reference
`[6].
`Furthermore,
`the
`propagation
`characteristic
`hugely
`depends on the environment around
`the
`receiver tennud.
`this case, the propagation model of d-i! (ftee
`Therefore, in
`space), d-3 and &4 law were adopted.
`Figure 6 shows the calculation result. When the propagation
`model of the &3 law is assumed, the acceptable LO leakage power
`are -80 dBm and -70 dBm at the edge of the cell, provided that
`the distances between the two terminals are 1 m and 3 m,
`respectively. Thus, the required attenuation for the LO
`leakage
`is -70 dB and -60 dB, respectively.
`The required attenuation values or isolations for the LO
`leakage power are summarized in Table 2.
`(4
`from tbe RF st.ge Coolpoaentsand cilmits
`In the above discussion, LO power is assumed to be radiated
`only
`from
`the receiving antenna. However, in a practical
`receiver, the LO power can also radiate from RF components and
`circuits, especially from
`In order to
`the LO circuit itself.
`determine the effect of
`radiation
`from RF components and
`circuits, the LO radiation power from a miniature receiver for
`the 280 MHz system was measured in an anechoic chamber using
`an antenna radiation characteristic measurement equipment[8].
`The measurement was carried out for the receiver to measure the
`LO power radiated directly from
`the RF circuit components
`without the receiver’s antenna.
`
`-
`
`The measurement showed that approximately -73 dBm LO
`power was radiated from the RF components and circuits. From
`in Table 1, about 15 dB
`this result and assumption shown
`attenuation is required for practical system applications. This
`can be achieved by shielding the LO circuit.
`4. Required RF Filter Specifications
`In this section, the RF filter specifications for the direct
`conversion
`receiver are discussed. The direct conversion
`receiver requires no image rejection filter. However, especially
`under outdoor radio communication environments, interference
`signals can cause nonlinear distortion, such as intermodulation
`or crossmodulation in the receiver RF stage. An interference
`the RF stage to attenuate
`rejection filter is inserted in
`undesired signals transmitted from other radio stations or
`adjacent
`terminals. The
`filter
`specifications should
`be
`determined to provide sufficient tolerance for practical system
`applications while still not being
`too strict for miniature
`receiver realization.
`the following discussion, VHF television and radio
`In
`broadcasting waves for a 280 MHz system, and transmitted
`signals from adjacent terminals for 900 MHz and 2.6 GHz
`systems are assumed to be the interference signals.
`
`(a) 280 MHz Band
`Bit error rate measurements were carried out on the test
`receiver under an actual outdoor radio wave environment. The
`bandwidth of the RF stage of the receiver was limited by that
`of the RF amplifier, the mixer, and the impedance matching
`circuits. The second order input intercept point (IP2) of the
`RF stage was -20 dBm. Fig. 7 shows the measurement principle
`blockdiagram. The incoming RF signal, the desired signal (D),
`is supplied by the signal generator. On the other hand, actual
`radio waves received by the antenna mounted on the roof of a
`four storied building located in Kawasaki City were adopted as
`an undesired interference signal (U). As frequencies adjacent
`to D (280 MHz), TV broadcast signals (approximately 90-108
`MHz and 170-220 MHz) and FM radio waves (80-90 MHz)
`mainly interfere with D in the receiver (Fig. 8). U varied by
`the attenuator and D from the signalgenerator were mixed and
`sent to the receiver input. The receiver output was fed to a
`bit error counter. The main factor that increased the BER
`the RF
`was revealed to be second order nonlinearity in
`amplifier and the mixer.
`The measurement was carried out three times in a similar
`manner. Almost the same results were obtained
`in each
`measurement, as shown in Fig. 9. The relations between the
`l@z BER were
`receiving D and U power required for a
`obtained from Fig. 9 and shown in Fig. IO. with a solid line.
`The broken lines in Fig. 10 show theoretical relations between
`D and U calculated with the assumed IP2 values of the
`RF stage based on the measurement result (the solid line). For
`example, when the receiver with the RF stage IP2 of -20 dBm
`receives -100 dBm D power and -30 dBm U power, an
`approximately 15 dB attenuation on U before the receiver
`h n t - e n d is required to obtain a 1W BER. The relation
`in Fig. 10 was verified by another experiment Carried out
`in the Tokyo area. Almost the same relation was obtained.
`From
`the relation indicated
`in Fig. 10, the required
`attenuation for undesired signals was calculated to determine
`the RF filter specifications in the direct conversion receiver.
`First, several conditions listed below were set for calculation.
`(1) The relation between D power and U power described in
`Fig. 10 generally holds.
`(2) The service area described in Fig. 11 was assumed. mere
`are one D station and one U station in the service area.
`in Fig. 11, were also
`Parameters for each station, given
`assumed. The distance between D station and U station was
`fixed at 3.5 km.
`
`458
`
`TCL EXHIBIT 1029
`Page 2 of 6
`
`

`
`(3) The antenna for any receiver terminal in the service area
`has the same actualgain in regard to D and U.
`(4) The RF stage parameters for the terminal shown in Table 3
`were assumed. The RF stage IP2 was approximately -40 dBm.
`(5) The vertical plane radiation pattern for the transmitting
`station antenna was a cosine beam of the 6th power for D and
`37th for U (Fig. 12).
`(6) The propagation characteristic model from Reference [6] was
`adopted for D and U.
`The calculation was carried out for simplicity for a
`terminal moving along a straight line from D station to U
`station. Since the strictest point in
`the service area exists
`on this line from an interference viewpoint, the calculation
`results can be treated without loss of generality.
`The results are shown in Fig. 13, where D and U power
`are at the receiver input with
`the receiver antenna's actual
`gain of -27 dBi (Table 1). Fig. 13 also shows the attenuation
`required to obtain a 10-2 BER calculated from
`for U
`the
`in Fig. 10. The largest attenuation on U, or the
`relation
`most strict outband rejection performance in a practical filter,
`is required in the terminal at an area about 5.5 km from the D
`station. At this area, the received signal power was -% dBm
`for D and -40 dBm for U. The required attenuation for U is
`about 15 dB. This is the result under statistical conditions.
`Under the condition of fading and shadowing listed in Table 1,
`an attenuation for D, approximately 35 dB, is required in
`a practical direct conversion receiver front-end
`for a 10-2
`average BER. This attenuation can be realized by either an
`RF
`filter or an outband
`rejection characteristic of
`the
`receiving antenna itself. When the receiver is equipped with
`a receiving antenna with an approximately 25 dB outband
`rejection, a practical value measured with a
`test miniature
`receiver, the required filter outband rejection for U
`is only
`about 10 dB.
`
`(b)IosertionPointofpilterandAmpli6erintbeRFStage
`The insertion point of the RF filter and the RF amplifier
`for a direct conversion
`receiver front-end were
`investigated.
`the previous discussion, the RF filter was assumed to be
`In
`inserted before the RF amplifier in the receiver front-end. This
`architecture is suitable to decrease nonlinear distortion caused
`in the RF circuits. However, an about 3 dB
`insertion loss is
`not negligible for receiver sensitivity. Thus, the RF amplifier
`RF filter
`for
`practical
`receiver
`should
`precede
`the
`implementation. Thus, an investigation on the required outband
`level for the RF
`filter is necessary
`to
`implement
`rejection
`this architecture.
`In the following, the RF stage distortion is represented by
`the second order input intercept point (IP2). The RF stage IP2
`value, the total IP2 value of the amplifier and mixer, in terms
`the RF filter outband attenuation level was calculated by
`of
`the formula in Reference [7] for the assumed miniature receiver
`with the RF component parameters shown in Table 3.
`From
`the result given
`in Fig. 14, when an RF filter is
`the RF amplifier, an RF
`inserted before
`filter with an
`approximately 10 dB outband rejection, which
`is equal to the
`required value discussed in (a), achieves a -20 dBm RF stage
`IP2. Thus, the approximately -20 dBm
`IP2
`is sufficient for a
`the other hand, when
`the
`filter is
`practical receiver. On
`inserted after
`the amplifier,
`infinite outband
`rejection
`is
`In this case, however, the filter with
`required
`theoretically.
`an approximately 15 dB outband rejection presents a -23 dBm
`tP2. This is only a 3 dB decrease from
`the required value.
`Therefore, it will be a negligible effect on system performance.
`Thus
`the
`required
`filter outband
`attenuation
`is
`relaxed
`about U) dB compared with the image rejection filter in a
`conventional super-heterodyne receiver.
`(c) 900 MHz and 2.6 GHz Band
`In
`a practical radio communication
`
`transmitted
`
`system,
`
`considered as
`should be
`terminals
`adjacent
`from
`signals
`in
`the same
`the
`receiver
`terminals
`interference signals for
`system. The
`interference signals cause
`saturation
`in
`the
`adjacent receiver front-end, and thus increase the BER. So they
`must be removed by an RF filter or some other means.
`Here, a 1-dB gain compression point of the mixer has been
`adopted as a measure for an acceptable interference input power.
`The interference was assumed to contain no TV broadcasting
`a negligible effect on receiver
`signals, since
`they have
`performance in 900 MHz and 2.6 GHz band systems.
`calculation was carried out for cases that the 1-dB gain
`compression point of the mixer were -10 dBm and -20 dBm with
`the distance between two terminals being fixed to 1 m. The
`result obtained by
`the above criterion is shown
`in Table 4,
`where 0 dBi antenna gain and 10 dB preamplifier power gain
`gain
`were assumed. Table 4 indicates that when
`the 1-dB
`compression point of the mixer satisfies -10 dBm, the required
`is not so strict
`outband characteristic
`for
`the
`filter
`in
`achieving filter miniaturization.
`
`5. Conclusion
`This paper describes the required RF stage performance for a
`direct conversion receiver for 280 MHz, 900 MHz, and 2.6 GHz
`system applications.
`leakage for
`the
`level for LO
`The required attenuation
`the
`assumed system
`terminal was calculated. Furthermore, from
`test receiver measurement result, it was found that LO circuit
`shielding is necessBfy for practical system applications.
`The required outband attenuation level of an RF filter for
`interference signals was also investigated quantitatively
`from
`the experimental data obtained from bit error rate measurements
`under an actual radb wave environment and from calculations
`based on a 1-dB gain compression point of the mixer. Thus, it
`has been
`found
`that an
`interference
`rejection
`filter
`is
`necessary
`for practical direct conversion
`receiver applications.
`filter specification has been largely
`relaxed
`However,
`the
`compared with
`the
`image rejection filter in a conventional
`super-heterodyne architecture.
`
`Acknowledgments
`The authors wish to thank Mr. T.Morooka of the Toshiba
`Research and Development Center for his valuable guidance.
`They are also indebted to Mr. F.Umibe of the Toshiba Research
`Consulting Corp. for reviewing and giving valuable comments to
`the originalEnglish manuscript.
`References
`[l]D.G.Tucker:" The History of the .Homodyne and Synchrodyne"
`J.British Inst. Radio Engineers, Vol.14, No.4, pp.143-154 (1954).
`[2]I.A.W.Vance:" An Integrated Circuit V.H.F. Radio Receiver" ,
`The Radio and Electronic Engineer, Vo1.50, No.4, pp.158-164
`(1980).
`[3]P.A.Moore:" A High-Performance Low-Power VHF Receiver
`Front End" , Proc. IEE Conf. on Mobile Radio System and
`Techniques, pp.16-20 (1984).
`[4]A.Bateman, D.M.Haines:" Direct Conversion Transceiver
`Design for Compact Low-Cost Portable Mobile Radio Terminals"
`Proc. IEEE Conf. VT-89, pp.57-62 (1989).
`[S]G.Schultes, A.L.Scholtz, E.Bonek, and P.Veith :" A New
`Incoherent Direct Conversion Receiver" , Proc. IEEE Conf.
`VT-90, pp.668-674 (1990).
`[6]M.Hata:" Empirical Formula for Propagation Loss in Land
`Mobile Radio Service" , IEEE Trans. VT-29, No.3,
`pp.317-325 (1980).
`[7]R.C.Sagers:" Intercept Point and Undesired Responses" ,
`IEEE Trans. VT-32, No.1, pp.121-133 (1983).
`[8]T.Maeda, TMorooka:" Radiation Efficiency Measurement
`for Small Antenna Using a New Radiation Characteristic
`Measurement Equipment " , Proc. ISAP 1989 pp.921-924 (1989).
`
`459
`
`TCL EXHIBIT 1029
`Page 3 of 6
`
`

`
`ANT 1
`
`8 = I
`
`
`
`FILTER
`Fig. 1: Receiver Blockdiagram
`
`-100
`
`Distance from Base Station I k m l
`Fig. 3: Acceptable LO Leakage Power versus Distance
`from Base Station for 280 MHz System
`
`Table 1: Assumed System Parameters
`Modulation Hand‘Hz’ &(:e::
`E’requency
` K 74%:
`~ H z )
`Data Rate [bpsl
`1. 2 k
`5 0 k
`Detection
`F1 ip-Flop
`Differential _
`Eb/NO M I *
`7
`1 3
`- 1 1 3
`Sensitivity [dBml
`- 1 2 5
`1 5
`Fading Yargin[dBl
`1 5
`6
`Shadowing Margin [dBl
`6
`3 k
`Zone Radius [ml
`9 k
`H a t a [SI
`H a t a [SI
`Propagation Model
`BS Tx Pr[W]
`2 5
`2 5 0
`7 0
`At Height [m]
`1 1 0
`At GainrdBil
`5. 1 5
`5. 1 5
`1. 5
`YS At Height [mi
`1. 5
`0
`At Gain[dBi]
`- 2 7
`-10
`U) Power[dBml
`- 1 0
`YS-MS Distance[m]
`1, 3
`1, 3
`* Required for lo-’ BER
`BS:l!ase Station MS:Mobile Station At:Antenna
`
`7z /4*&:
`5 0 k
`Differential -
`‘I
`- 1 1 3
`1 5
`8
`2 0 0
`d-’
`0. 1
`3
`5. 1 5
`1. 5
`0
`- 1 0
`1, 3
`
`2ot
`
`-15
`
`I O
`
`2 0
`15
`E b / N O [ d B l
`Fig. 4: Required D/I versus Eb/NO
`for n/4-QPSK Receiver
`
`Llj
`0
`
`1 5
`
`2 5
`2 0
`E b / N O [ d B 1
`Fig. 2: Required D/I versus Eb/NO
`for FSK Receiver
`
`\
`
`4
`
`----__
`
`-100
`
`I
`
`2
`Distance from Base Station Ckm3
`Fig. 5: Acceptable LO Leakage Power versus Distance
`from Base Station for 900 MHz System
`
`460
`
`TCL EXHIBIT 1029
`Page 4 of 6
`
`

`
`propagation W e l :
`
`200
`100
`Distance from Base Station Cml
`Fig. 6: Acceptable LO Leakage Power versus Distance
`from Base Station for 2.6 GHz System
`
`I
`
`J
`
`-1001
`
`r
`
`0
`
`500M
`
`1G [Hz]
`
`Fig. 8: Interference Signal Spectrum
`
`BER
`
`DtdBal'
`
`Required
`
`ON ROOF OF
`
`Fig. 7: Bit 'Error Measurement Blockdiagram
`
`10-51
`
`Measurement
`Measurement
`Measurement
`
`I
`
`t
`
` -30
`-60
`-50
`-40
`Undesired signal Level [dBml
`
`Fig. 9: BER versus Undesired Signal Level
`
`RF Stage
`IPz [dBmI:
`(Fig.9)
`
`n - 2 0 -
`E ep
`U
`-30 3
`-40 -
`
`0 .
`
`-60 - )' 0 /
`
`0
`
`-120 -110 -100 -90 -80
`
`-70 -60 D [dBmJ
`Fig. 10: Desired Signal versus
`Undesired Signal for lo-'
`
`BER
`
`461
`
`TCL EXHIBIT 1029
`Page 5 of 6
`
`

`
`Ant Height:110 m
`Ant Gain :5.15 dBi
`Tx Power :250 W
`Paging Base Station(D)
`
`Ant Height:1.5 m
`Ant Gain :-27 dBi
`Receiver Terminal (MS)
`
`Ant Height:330 m
`Ant Gain :9.15 dBi
`Tx Power :50 kW
`TV & FM Broadcastim Station(U1
`(Tokyo Tower)
`
`Fig. 11: Assumed Wide-Area System
`
`Table 3: RF Stage Paraters
`RF h p GP
`10 dB
`-20 dBn
`-30 dBa
`
`IP2
`Mixer IP2
`
`- D Stotion
`---- U Station
`
`-501
`
`1-120
`
`D Station
`U Station
`Distance from Base Station
`(Base Station)
`[!-I
`Fig. 13: Required Attenuation for Undesired Signals
`versus Distance from Base Station
`
`8 lo-
`E p -IO-
`
`cu 0 -
`
`W m
`
`I
`I I
`I /
`/
`
`I
`
`I
`I
`
`---- RF
`-RF
`
`- RF-Amp.
`Filter
`RF Filter
`Amp. -
`
`,
`,
`,
`-501
`0 IO 20 30
`RF Filter Outband Rejection [dB1
`Fig. 14: Intercept Point on RF Stage versus
`Outband Rejection of RF Filter
`
`Fig. 12: Transmitting Antenna Radiation Pattern
`
`GC:Gain Conpression Point
`
`462
`
`TCL EXHIBIT 1029
`Page 6 of 6