Design and Analysis of Broadband High Isolation of Discrete Packaged PIN Diode SPDT Switch for Wireless Data Communication.
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
Design and Analysis of Broadband High Isolation of
Discrete Packaged PIN Diode SPDT Switch for
Wireless Data Communication
N. A. Shairi, B. H. Ahmad, A. C. Z. Khang
Telecommunication Engineering Department,
Faculty of Electronics and Computer Engineering,
Universiti Teknikal Malaysia Melaka (UTeM),
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia.
noorazwan@utem.edu.my, badrulhisham@utem.edu.my, arthur_chow12@yahoo.com
Abstract— A design and analysis of broadband high isolation of
discrete packaged PIN diode Single-Pole Double-Throw (SPDT)
switch is presented. Many applications of wireless data
communication are implementing Time Division Duplex (TDD)
switching such as UMTS-TDD (in 3G technologies), LTE (in 4G
technologies), HiperLAN, HiperMAN, WiFi, WiMAX and
WiBRO. A broadband high isolation of SPDT switch is needed to
provide these multimarket applications at different frequency
bands. In this paper, three different circuit topologies (Type A,
Type B and Type C) targeted for broadband high isolation are
designed and analyzed. The SPDT switches are based on the
discrete packaged PIN diode that available in the market for
switching control. Analysis of the various configurations is done
in order to select the most suitable topology for broadband high
isolation SPDT switch. As results, Type C has been chosen for
prototyping and measurement. In simulation and measurement,
the isolation is higher than 25 dB from 0.5 to 3 GHz compared
with Type A and Type B.
surrounding package lead frame [1] affecting especially at high
frequencies; but with circuit design techniques, a good
topology for broadband performance is possible to achieve.
Keywords-broadband high isolation, SPDT switch, switch
topology.
The selections of SPDT switch are depend on the
requirement of low insertion loss, high isolation, small circuit
size and low operating current [1-2], but with another
requirement of broadband high isolation, designers have to
select a suitable circuit topology to meet these requirements.
Thus there are different types of broadband high isolation
SPDT switch configuration such as shunt connection and
combination of series shunt connection as discussed below.
I.
Figure 1. SPDT switch in RF transceiver system
II.
INTRODUCTION
SPDT switch is commonly used in RF transceiver system to
perform Time Division Duplex (TDD) switching for transmit
and receive operation (see Figure 1). Many applications are
implementing TDD such as UMTS-TDD (in 3G technologies),
LTE (in 4G technologies), HiperLAN, HiperMAN, WiFi,
WiMAX and WiBRO. Therefore, a broadband high isolation
for SPDT switch is needed to provide these multimarket
applications at different frequency bands. This design will
reduce the cost of design and manufacturing.
A. Single Shunt Switch (Type A)
Paper in [3] proposed single shunt PIN diode connection
with quarter wavelengths (λ/4) of transmission line as shown
in Figure 2. The insertion loss of such connection is depending
on its junction capacitance (Cj), while the isolation is
depending on its series resistance (Rs) in the PIN diode. Such
connection will get better isolation compared to series PIN
diode connection [4-5].
In order to get wider bandwidth of isolation, a quarter
wavelength transmission line at f0 is placed between the
common junction and antenna port with some value of
impedance, Z1, below 50 Ω. The specific value of impedance
that is chosen will determine the SWR and bandwidth of the
switch [3].
By using discrete packaged PIN diode that available in the
market for switching control, this paper therefore focused on
circuit topology in order to get broadband high isolation. The
PIN diodes of HSMP-389Y from Avago Technologies are used
for switching control and three different topologies (Type A,
Type B and Type C) are designed and analyzed for the
performance. Generally, there is almost difficult to get
broadband high isolation if using single discrete packaged PIN
diode. This is due to inductance of bondwires and lead frames,
ground inductance and coupling between the RF line and the
This work was supported by Centre For Research And Innovation
Management (CRIM), Universiti Teknikal Malaysia Melaka (UTeM). Melaka,
Malaysia under Short Term Research Grant.
978-1-4577-1631-7/$26.00 © 2011 IEEE
SELECTION OF CIRCUIT TOPOLOGY
91
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
inductance. This resonance reduces the capacitive effect near
the resonance frequency and consequently increases the
isolation performance at that particular frequency. The
resistance from resistor is used to reduce the quality factor of
the resonance thus to improve the positive effect introduced by
the inductance for a wideband of frequencies [6].
Figure 2. Single shunt switch with quarter wavelenght transmission lines [3].
B. Series-Shunt Switch (Type B)
Higher isolation can be achieved by using a series-shunt
connection where isolations greater than the sum of that
obtained with a single series and a single parallel diode may
be obtained [4]. The series PIN diode can act as high
impedance in reverse bias, thus increasing the isolation.
However, there is an increase in bias circuit complexity
because all diodes are not simultaneously biased in one state
or the other [5].
The series-shunt PIN diode connection is added with three
quarter wavelengths as shown in Figure 3. This circuit
topology can have a broadband high isolation with the
combination of series-shunt PIN diode and the impedance of
quarter wavelength, Z1 where the functional and operational of
Z1 is the same with Type A.
Figure 4. Circuit topology of series-shunt-shunt connection
III.
SIMULATION RESULT AND ANALYSIS
The SPDT switch of Type A, Type B and Type C have
been simulated in Advanced Design System (ADS) software.
The topologies are simulated with the ideal component except
the PIN diode (based on HSMP-389Y from Avago
Technologies). Since all the topologies are symmetry, the
isolation and insertion loss results in transmit and receive mode
are the same. Thus only the transmit mode is analyzed in this
paper. The simulation results of insertion loss (S21) and
isolation (S13) in transmit mode are shown in Figure 5 where
these topologies are plotted in the same graph.
In Figure 5(a), Type A and B give better insertion loss
compared with Type C which is in average at 0.5 dB of losses.
A main issue in Type A and B is the limitation of quarter
wavelength of Z2 and Z3 during the on-state of shunt PIN
diode. The Z2 and Z3 operate at very narrow bandwidth. This
issue has been stated in [3]. This cause a very limited
bandwidth of insertion loss of Type A and Type B compared
with Type C. Thus any quarter wavelength transmission line
should be avoided in transmit and receive arm in broadband
SPDT switch design.
Figure 3. Series-shunt switch with quarter wavelenght transmission lines.
C. Series-Shunt-Shunt Switch (Type C)
The insertion loss of Type C is about 1 dB which is slightly
higher than Type A and Type B. This is due to series resistor
connected in parallel with series PIN diode in both transmit and
receive arm. This resistor causes a high impedance of the
transmission line and consequently attenuating the RF signal.
However, the insertion loss of Type C is almost constant across
the frequency band.
In [6-8], the series-shunt-shunt topology has been
implemented for SPDT switch of wireless data
communication. As shown in Figure 4, the circuit topology
consists of single series PIN diode and two shunt PIN diode of
each transmit and receive part. The two cascaded shunt PIN
diode will increase the isolation of 6 dB of each additional
shunt PIN diode [4].
However, the isolation of series PIN diode will decrease
when the frequency is increased. This is due to the rise of
junction capacitance (Cj) or parasitic capacitance as a function
of frequency. To overcome this isolation problem at high
frequencies, the compensation concept in [9] is used where a
series resistor and inductor are connected in parallel with
series PIN diode (Figure 4). When PIN diode is in off-state,
the parasitic capacitance of the PIN diode resonates with the
As shown in Figure 5(b), Type C gives higher isolation
which is higher than 20 dB across the frequencies compared
with Type A and Type B. Two elements have contributed to
the higher isolation in Type C, which are the parallel inductor
with the series PIN diode and the additional shunt PIN diode in
the both transmit and receive mode. The series resistor parallel
with series PIN diode is purposely used to get broadband
isolation at high frequencies. That is why in Type B, with the
series PIN diode, it has shown better improvement of isolation
compared with Type A but without a series resistor and
92
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
Ω. The Type C prototype has been measured using network
analyzer for the actual insertion loss and isolation performance.
inductor parallel with series PIN diode, the isolation has
dropped significantly at 3 GHz and above.
Figure 6. SPDT switch prototype (Type C)
(a)
Figure 7 shows the comparison between simulation and
isolation of insertion loss and isolation. Since the ideal
component of inductor, capacitor and transmission line have
been used in the simulation, the measured insertion loss is
slightly higher than the simulated result. This includes the
losses of SMA connectors.
(b)
Figure 5. S-parameter simulation of Type A, B and C in transmit mode (a)
Insertion Loss (b) Isolation.
In summary, Type A gives advantages in term of
simplicity of circuit and has lower insertion loss, but lacks in
term of isolation performance. Type B has high isolation and
low insertion loss but in very limited bandwidth only at low
frequency. In Type C, the broadband high isolation has been
achieved but lacks in term of insertion loss performance. Thus,
this is a trade-off of between isolation and insertion loss
performance in this topology. Since this paper is targeted for
broadband high isolation, Type C has been selected for
fabrication and prototyping.
IV.
(a)
SWITCH PROTOTYPING AND MEASUREMENT RESULT
As shown in Figure 6, the circuit topology Type C has been
fabricated on FR4 substrate having thickness of 1.6 mm, a
dielectric constant r of 4.7, microstrip line thickness of 0.035
mm and a loss tangent, tan of 0.019. The microstrip line
width of 3 mm is used for the characteristic impedance of 50
(b)
Figure 7. S-parameter simulation versus measurement (a) Insertion Loss (b)
Isolation.
93
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
REFERENCES
In the isolation graph, the measured isolation is higher than
25 dB. Take note that the isolation of SPDT switch is mainly
influenced by PIN diode. The differences between simulation
and measurement are depending on the PIN diode modeling in
the simulation and the actual PIN diode in the measurement.
The actual packaged PIN diodes have tolerance values thus
resulting in different measurement result compared with
simulation.
[1]
[2]
[3]
[4]
V.
CONCLUSION
[5]
Three different SPDT switch topologies targeted for
broadband high isolation SPDT switch have been selected and
simulated in ADS software. There are single shunt topology
(Type A), series-shunt topology (Type B) and series-shuntshunt topology (Type C). The PIN diodes which are HSMP389Y from Avago Technologies have been used for switching
control. From the simulation results, Type C has shown
broadband high isolation from 0.5 GHz to 4 GHz compared
with Type A and Type B. Then, the Type C topology has been
fabricated on FR4 board and measured with network analyzer
for verification. The measured isolation has agreed with the
simulation which is higher than 25 dB across the frequencies.
[6]
[7]
[8]
[9]
ACKNOWLEDGMENT
The work described in this paper was fully supported by
Centre For Research And Innovation Management (CRIM),
Universiti Teknikal Malaysia Melaka (UTeM). Melaka,
Malaysia under Short Tearm Research Grant.
94
Kai Chang, Inder Bahl and Vijay Nair. RF and Microwave Circuit and
Component Design for Wireless Systems. Third Avenue, N.Y.: John
Wiley & Sons, Inc. 2002.
An SPDT PIN Diode T/R Switch for PCN Application. Avago
Technologies. December 16, 2006.
Avago Technologies. Broadbanding the Shunt PIN Diode SPDT Switch.
Appplication Note 957-1 11, December 2006.
Avago Technologies. Application of PIN diode, Application notes 922.
December 11, 2006.
Microsemi Corporation. The PIN Diode Circuit Designers’ Handbook.
USA: Handbook. 1998
V.Alleva, A.Bettidi, A.Cetronio, W.Ciccognani, M. De Dominicis,
M.Ferrari, E.Giovine, C.Lanzieri, E. Limiti, A. Megna, M. Peroni and P.
Romanini. High Power Microstrip GaN-HEMT Switches for Microwave
Applications. 3rd European Microwave Integrated Circuits Conference.
Oct 2008.
Jar-Lon Lee, Donna Zych, Elias Reese and Denis M. Drury. Monolithic
2-18GHz Low Loss, On-chip Biased PIN Diode Switches. IEEE Trans.
Microwave Techniques. Feb 1995.
Campbell, C.F. Dumka, D.C. , Wideband high power GaN on SiC SPDT
switch MMICs, Microwave Symposium Digest (MTT), 2010 IEEE
MTT-S International. pp. 145.
A. Ezzeddine, R. Pengelly, H. Badawi, A High Isolation DC to 18GHz
Packaged MMIC SPDT Switch, European Microwave Conference,
October 1988,pp. 1028-1033.
Design and Analysis of Broadband High Isolation of
Discrete Packaged PIN Diode SPDT Switch for
Wireless Data Communication
N. A. Shairi, B. H. Ahmad, A. C. Z. Khang
Telecommunication Engineering Department,
Faculty of Electronics and Computer Engineering,
Universiti Teknikal Malaysia Melaka (UTeM),
Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia.
noorazwan@utem.edu.my, badrulhisham@utem.edu.my, arthur_chow12@yahoo.com
Abstract— A design and analysis of broadband high isolation of
discrete packaged PIN diode Single-Pole Double-Throw (SPDT)
switch is presented. Many applications of wireless data
communication are implementing Time Division Duplex (TDD)
switching such as UMTS-TDD (in 3G technologies), LTE (in 4G
technologies), HiperLAN, HiperMAN, WiFi, WiMAX and
WiBRO. A broadband high isolation of SPDT switch is needed to
provide these multimarket applications at different frequency
bands. In this paper, three different circuit topologies (Type A,
Type B and Type C) targeted for broadband high isolation are
designed and analyzed. The SPDT switches are based on the
discrete packaged PIN diode that available in the market for
switching control. Analysis of the various configurations is done
in order to select the most suitable topology for broadband high
isolation SPDT switch. As results, Type C has been chosen for
prototyping and measurement. In simulation and measurement,
the isolation is higher than 25 dB from 0.5 to 3 GHz compared
with Type A and Type B.
surrounding package lead frame [1] affecting especially at high
frequencies; but with circuit design techniques, a good
topology for broadband performance is possible to achieve.
Keywords-broadband high isolation, SPDT switch, switch
topology.
The selections of SPDT switch are depend on the
requirement of low insertion loss, high isolation, small circuit
size and low operating current [1-2], but with another
requirement of broadband high isolation, designers have to
select a suitable circuit topology to meet these requirements.
Thus there are different types of broadband high isolation
SPDT switch configuration such as shunt connection and
combination of series shunt connection as discussed below.
I.
Figure 1. SPDT switch in RF transceiver system
II.
INTRODUCTION
SPDT switch is commonly used in RF transceiver system to
perform Time Division Duplex (TDD) switching for transmit
and receive operation (see Figure 1). Many applications are
implementing TDD such as UMTS-TDD (in 3G technologies),
LTE (in 4G technologies), HiperLAN, HiperMAN, WiFi,
WiMAX and WiBRO. Therefore, a broadband high isolation
for SPDT switch is needed to provide these multimarket
applications at different frequency bands. This design will
reduce the cost of design and manufacturing.
A. Single Shunt Switch (Type A)
Paper in [3] proposed single shunt PIN diode connection
with quarter wavelengths (λ/4) of transmission line as shown
in Figure 2. The insertion loss of such connection is depending
on its junction capacitance (Cj), while the isolation is
depending on its series resistance (Rs) in the PIN diode. Such
connection will get better isolation compared to series PIN
diode connection [4-5].
In order to get wider bandwidth of isolation, a quarter
wavelength transmission line at f0 is placed between the
common junction and antenna port with some value of
impedance, Z1, below 50 Ω. The specific value of impedance
that is chosen will determine the SWR and bandwidth of the
switch [3].
By using discrete packaged PIN diode that available in the
market for switching control, this paper therefore focused on
circuit topology in order to get broadband high isolation. The
PIN diodes of HSMP-389Y from Avago Technologies are used
for switching control and three different topologies (Type A,
Type B and Type C) are designed and analyzed for the
performance. Generally, there is almost difficult to get
broadband high isolation if using single discrete packaged PIN
diode. This is due to inductance of bondwires and lead frames,
ground inductance and coupling between the RF line and the
This work was supported by Centre For Research And Innovation
Management (CRIM), Universiti Teknikal Malaysia Melaka (UTeM). Melaka,
Malaysia under Short Term Research Grant.
978-1-4577-1631-7/$26.00 © 2011 IEEE
SELECTION OF CIRCUIT TOPOLOGY
91
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
inductance. This resonance reduces the capacitive effect near
the resonance frequency and consequently increases the
isolation performance at that particular frequency. The
resistance from resistor is used to reduce the quality factor of
the resonance thus to improve the positive effect introduced by
the inductance for a wideband of frequencies [6].
Figure 2. Single shunt switch with quarter wavelenght transmission lines [3].
B. Series-Shunt Switch (Type B)
Higher isolation can be achieved by using a series-shunt
connection where isolations greater than the sum of that
obtained with a single series and a single parallel diode may
be obtained [4]. The series PIN diode can act as high
impedance in reverse bias, thus increasing the isolation.
However, there is an increase in bias circuit complexity
because all diodes are not simultaneously biased in one state
or the other [5].
The series-shunt PIN diode connection is added with three
quarter wavelengths as shown in Figure 3. This circuit
topology can have a broadband high isolation with the
combination of series-shunt PIN diode and the impedance of
quarter wavelength, Z1 where the functional and operational of
Z1 is the same with Type A.
Figure 4. Circuit topology of series-shunt-shunt connection
III.
SIMULATION RESULT AND ANALYSIS
The SPDT switch of Type A, Type B and Type C have
been simulated in Advanced Design System (ADS) software.
The topologies are simulated with the ideal component except
the PIN diode (based on HSMP-389Y from Avago
Technologies). Since all the topologies are symmetry, the
isolation and insertion loss results in transmit and receive mode
are the same. Thus only the transmit mode is analyzed in this
paper. The simulation results of insertion loss (S21) and
isolation (S13) in transmit mode are shown in Figure 5 where
these topologies are plotted in the same graph.
In Figure 5(a), Type A and B give better insertion loss
compared with Type C which is in average at 0.5 dB of losses.
A main issue in Type A and B is the limitation of quarter
wavelength of Z2 and Z3 during the on-state of shunt PIN
diode. The Z2 and Z3 operate at very narrow bandwidth. This
issue has been stated in [3]. This cause a very limited
bandwidth of insertion loss of Type A and Type B compared
with Type C. Thus any quarter wavelength transmission line
should be avoided in transmit and receive arm in broadband
SPDT switch design.
Figure 3. Series-shunt switch with quarter wavelenght transmission lines.
C. Series-Shunt-Shunt Switch (Type C)
The insertion loss of Type C is about 1 dB which is slightly
higher than Type A and Type B. This is due to series resistor
connected in parallel with series PIN diode in both transmit and
receive arm. This resistor causes a high impedance of the
transmission line and consequently attenuating the RF signal.
However, the insertion loss of Type C is almost constant across
the frequency band.
In [6-8], the series-shunt-shunt topology has been
implemented for SPDT switch of wireless data
communication. As shown in Figure 4, the circuit topology
consists of single series PIN diode and two shunt PIN diode of
each transmit and receive part. The two cascaded shunt PIN
diode will increase the isolation of 6 dB of each additional
shunt PIN diode [4].
However, the isolation of series PIN diode will decrease
when the frequency is increased. This is due to the rise of
junction capacitance (Cj) or parasitic capacitance as a function
of frequency. To overcome this isolation problem at high
frequencies, the compensation concept in [9] is used where a
series resistor and inductor are connected in parallel with
series PIN diode (Figure 4). When PIN diode is in off-state,
the parasitic capacitance of the PIN diode resonates with the
As shown in Figure 5(b), Type C gives higher isolation
which is higher than 20 dB across the frequencies compared
with Type A and Type B. Two elements have contributed to
the higher isolation in Type C, which are the parallel inductor
with the series PIN diode and the additional shunt PIN diode in
the both transmit and receive mode. The series resistor parallel
with series PIN diode is purposely used to get broadband
isolation at high frequencies. That is why in Type B, with the
series PIN diode, it has shown better improvement of isolation
compared with Type A but without a series resistor and
92
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
Ω. The Type C prototype has been measured using network
analyzer for the actual insertion loss and isolation performance.
inductor parallel with series PIN diode, the isolation has
dropped significantly at 3 GHz and above.
Figure 6. SPDT switch prototype (Type C)
(a)
Figure 7 shows the comparison between simulation and
isolation of insertion loss and isolation. Since the ideal
component of inductor, capacitor and transmission line have
been used in the simulation, the measured insertion loss is
slightly higher than the simulated result. This includes the
losses of SMA connectors.
(b)
Figure 5. S-parameter simulation of Type A, B and C in transmit mode (a)
Insertion Loss (b) Isolation.
In summary, Type A gives advantages in term of
simplicity of circuit and has lower insertion loss, but lacks in
term of isolation performance. Type B has high isolation and
low insertion loss but in very limited bandwidth only at low
frequency. In Type C, the broadband high isolation has been
achieved but lacks in term of insertion loss performance. Thus,
this is a trade-off of between isolation and insertion loss
performance in this topology. Since this paper is targeted for
broadband high isolation, Type C has been selected for
fabrication and prototyping.
IV.
(a)
SWITCH PROTOTYPING AND MEASUREMENT RESULT
As shown in Figure 6, the circuit topology Type C has been
fabricated on FR4 substrate having thickness of 1.6 mm, a
dielectric constant r of 4.7, microstrip line thickness of 0.035
mm and a loss tangent, tan of 0.019. The microstrip line
width of 3 mm is used for the characteristic impedance of 50
(b)
Figure 7. S-parameter simulation versus measurement (a) Insertion Loss (b)
Isolation.
93
2011 IEEE International RF and Microwave Conference (RFM 2011), 12th - 14th December 2011, Seremban, Malaysia
REFERENCES
In the isolation graph, the measured isolation is higher than
25 dB. Take note that the isolation of SPDT switch is mainly
influenced by PIN diode. The differences between simulation
and measurement are depending on the PIN diode modeling in
the simulation and the actual PIN diode in the measurement.
The actual packaged PIN diodes have tolerance values thus
resulting in different measurement result compared with
simulation.
[1]
[2]
[3]
[4]
V.
CONCLUSION
[5]
Three different SPDT switch topologies targeted for
broadband high isolation SPDT switch have been selected and
simulated in ADS software. There are single shunt topology
(Type A), series-shunt topology (Type B) and series-shuntshunt topology (Type C). The PIN diodes which are HSMP389Y from Avago Technologies have been used for switching
control. From the simulation results, Type C has shown
broadband high isolation from 0.5 GHz to 4 GHz compared
with Type A and Type B. Then, the Type C topology has been
fabricated on FR4 board and measured with network analyzer
for verification. The measured isolation has agreed with the
simulation which is higher than 25 dB across the frequencies.
[6]
[7]
[8]
[9]
ACKNOWLEDGMENT
The work described in this paper was fully supported by
Centre For Research And Innovation Management (CRIM),
Universiti Teknikal Malaysia Melaka (UTeM). Melaka,
Malaysia under Short Tearm Research Grant.
94
Kai Chang, Inder Bahl and Vijay Nair. RF and Microwave Circuit and
Component Design for Wireless Systems. Third Avenue, N.Y.: John
Wiley & Sons, Inc. 2002.
An SPDT PIN Diode T/R Switch for PCN Application. Avago
Technologies. December 16, 2006.
Avago Technologies. Broadbanding the Shunt PIN Diode SPDT Switch.
Appplication Note 957-1 11, December 2006.
Avago Technologies. Application of PIN diode, Application notes 922.
December 11, 2006.
Microsemi Corporation. The PIN Diode Circuit Designers’ Handbook.
USA: Handbook. 1998
V.Alleva, A.Bettidi, A.Cetronio, W.Ciccognani, M. De Dominicis,
M.Ferrari, E.Giovine, C.Lanzieri, E. Limiti, A. Megna, M. Peroni and P.
Romanini. High Power Microstrip GaN-HEMT Switches for Microwave
Applications. 3rd European Microwave Integrated Circuits Conference.
Oct 2008.
Jar-Lon Lee, Donna Zych, Elias Reese and Denis M. Drury. Monolithic
2-18GHz Low Loss, On-chip Biased PIN Diode Switches. IEEE Trans.
Microwave Techniques. Feb 1995.
Campbell, C.F. Dumka, D.C. , Wideband high power GaN on SiC SPDT
switch MMICs, Microwave Symposium Digest (MTT), 2010 IEEE
MTT-S International. pp. 145.
A. Ezzeddine, R. Pengelly, H. Badawi, A High Isolation DC to 18GHz
Packaged MMIC SPDT Switch, European Microwave Conference,
October 1988,pp. 1028-1033.