IEEE Circuits and Systems Magazine - Q4 2020 - 14

drive loads [69]. However, this configuration can affect
the start-up time of the oscillator, one solution can be to
connect the resonator to VDD instead of ground as suggested by [70]. Another approach to improve the common drain Colpitts driving capability, is to use a cascade
of a common drain amplifier as shown in Fig. 11. Compared to the cascode circuit presented in Fig. 10, it can
run on lower voltages as it has fewer stacked transistors.

MN1
C1

FBAR

C2

C

MN3
CC
MN4

MN2

Vout
Vbias

Figure 11. Cascade of a common drain amplifier and common drain Colpitts topology.

Vbias3

C1
FBAR

Cc2

MP1
MN1
Cc1

MN3

Vout

C2

C

MN2

Vbias1

MN4

Vbias2

Fig. 12 shows a modified version of the circuit in Fig. 11,
where the output is fed back to the drain of the oscillator
to improve the gain at high frequencies [71].
In [72] the authors propose an inductively compensation method as shown in Fig. 13 to compensate for
the gate-drain parasitic capacitance, which reduces
the gain of the amplifier. The capacitance Cc is just a
coupling capacitor to block DC and avoid short circuit
across the gate and drain.
The common drain Colpitts can be modified to run
on higher harmonics [73], [74] of a resonator, often referred to as overtone Colpitts. Fig. 14 shows an overtone
Colpitts presented in [75]. The feedback circuit at the
source of the transistor consists of the capacitors C1,
Cr, and the inductor Lr. Lr and Cr are tuned to reject the
fundamental frequency. The tank circuit at the drain,
(Cs and Ls) is used to select the desired overtone.
The overtone circuit in [75] was designed in 90 nm
CMOS technology and connected to an FBAR with a fundamental frequency at 1.87 GHz. Overtone frequencies
were measured at 4.78 GHz, 7.06 GHz, and 8.76 GHz for
second, third and fourth overtones respectively. The oscillator was tuned to operate on the third overtone at
7.06 GHz, which gave a measured oscillator frequency
of 6.3 GHz. The total power consumption was 475 nW
and the phase noise at 1 MHz offset was -110 dBc/Hz.
This overtone method can affect the start-up time of the
oscillator, one solution can be connecting the FBAR to
VDD instead of ground [67].
Another improvement to the common drain is proposed by [53] as shown in Fig. 15. According to this publication, placing the inductor LNF between the output
and the load transistor MN2 improves the noise properties of the oscillator.

Figure 12. Cascade of a common drain amplifier and common drain Colpitts with a feedback [71].

Cc

Cs

MN1
C1

C1
FBAR

C2
MN2

Vbias

Figure 13. Inductively compensate the parasitic gate-drain
capacitance [72].
14â

Vout

MN1
Vout

FBAR

C

Ls

Lc

C

Cr

Lr

Figure 14. Overtone common drain Colpitts topology [75]. Cr
and L r are tuned to reject the fundamental frequency and Cs
and L s to select the desired overtone.

IEEE CIRCUITS AND SYSTEMS MAGAZINE

FOURTH QUARTER 2020

IEEE Circuits and Systems Magazine - Q4 2020

Table of Contents for the Digital Edition of IEEE Circuits and Systems Magazine - Q4 2020

Contents
IEEE Circuits and Systems Magazine - Q4 2020 - Cover1
IEEE Circuits and Systems Magazine - Q4 2020 - Cover2
IEEE Circuits and Systems Magazine - Q4 2020 - Contents
IEEE Circuits and Systems Magazine - Q4 2020 - 2
IEEE Circuits and Systems Magazine - Q4 2020 - 3
IEEE Circuits and Systems Magazine - Q4 2020 - 4
IEEE Circuits and Systems Magazine - Q4 2020 - 5
IEEE Circuits and Systems Magazine - Q4 2020 - 6
IEEE Circuits and Systems Magazine - Q4 2020 - 7
IEEE Circuits and Systems Magazine - Q4 2020 - 8
IEEE Circuits and Systems Magazine - Q4 2020 - 9
IEEE Circuits and Systems Magazine - Q4 2020 - 10
IEEE Circuits and Systems Magazine - Q4 2020 - 11
IEEE Circuits and Systems Magazine - Q4 2020 - 12
IEEE Circuits and Systems Magazine - Q4 2020 - 13
IEEE Circuits and Systems Magazine - Q4 2020 - 14
IEEE Circuits and Systems Magazine - Q4 2020 - 15
IEEE Circuits and Systems Magazine - Q4 2020 - 16
IEEE Circuits and Systems Magazine - Q4 2020 - 17
IEEE Circuits and Systems Magazine - Q4 2020 - 18
IEEE Circuits and Systems Magazine - Q4 2020 - 19
IEEE Circuits and Systems Magazine - Q4 2020 - 20
IEEE Circuits and Systems Magazine - Q4 2020 - 21
IEEE Circuits and Systems Magazine - Q4 2020 - 22
IEEE Circuits and Systems Magazine - Q4 2020 - 23
IEEE Circuits and Systems Magazine - Q4 2020 - 24
IEEE Circuits and Systems Magazine - Q4 2020 - 25
IEEE Circuits and Systems Magazine - Q4 2020 - 26
IEEE Circuits and Systems Magazine - Q4 2020 - 27
IEEE Circuits and Systems Magazine - Q4 2020 - 28
IEEE Circuits and Systems Magazine - Q4 2020 - 29
IEEE Circuits and Systems Magazine - Q4 2020 - 30
IEEE Circuits and Systems Magazine - Q4 2020 - 31
IEEE Circuits and Systems Magazine - Q4 2020 - 32
IEEE Circuits and Systems Magazine - Q4 2020 - 33
IEEE Circuits and Systems Magazine - Q4 2020 - 34
IEEE Circuits and Systems Magazine - Q4 2020 - 35
IEEE Circuits and Systems Magazine - Q4 2020 - 36
IEEE Circuits and Systems Magazine - Q4 2020 - 37
IEEE Circuits and Systems Magazine - Q4 2020 - 38
IEEE Circuits and Systems Magazine - Q4 2020 - 39
IEEE Circuits and Systems Magazine - Q4 2020 - 40
IEEE Circuits and Systems Magazine - Q4 2020 - 41
IEEE Circuits and Systems Magazine - Q4 2020 - 42
IEEE Circuits and Systems Magazine - Q4 2020 - 43
IEEE Circuits and Systems Magazine - Q4 2020 - 44
IEEE Circuits and Systems Magazine - Q4 2020 - 45
IEEE Circuits and Systems Magazine - Q4 2020 - 46
IEEE Circuits and Systems Magazine - Q4 2020 - 47
IEEE Circuits and Systems Magazine - Q4 2020 - 48
IEEE Circuits and Systems Magazine - Q4 2020 - 49
IEEE Circuits and Systems Magazine - Q4 2020 - 50
IEEE Circuits and Systems Magazine - Q4 2020 - 51
IEEE Circuits and Systems Magazine - Q4 2020 - 52
IEEE Circuits and Systems Magazine - Q4 2020 - 53
IEEE Circuits and Systems Magazine - Q4 2020 - 54
IEEE Circuits and Systems Magazine - Q4 2020 - 55
IEEE Circuits and Systems Magazine - Q4 2020 - 56
IEEE Circuits and Systems Magazine - Q4 2020 - 57
IEEE Circuits and Systems Magazine - Q4 2020 - 58
IEEE Circuits and Systems Magazine - Q4 2020 - 59
IEEE Circuits and Systems Magazine - Q4 2020 - 60
IEEE Circuits and Systems Magazine - Q4 2020 - 61
IEEE Circuits and Systems Magazine - Q4 2020 - 62
IEEE Circuits and Systems Magazine - Q4 2020 - 63
IEEE Circuits and Systems Magazine - Q4 2020 - 64
IEEE Circuits and Systems Magazine - Q4 2020 - 65
IEEE Circuits and Systems Magazine - Q4 2020 - 66
IEEE Circuits and Systems Magazine - Q4 2020 - 67
IEEE Circuits and Systems Magazine - Q4 2020 - 68
IEEE Circuits and Systems Magazine - Q4 2020 - 69
IEEE Circuits and Systems Magazine - Q4 2020 - 70
IEEE Circuits and Systems Magazine - Q4 2020 - 71
IEEE Circuits and Systems Magazine - Q4 2020 - 72
IEEE Circuits and Systems Magazine - Q4 2020 - 73
IEEE Circuits and Systems Magazine - Q4 2020 - 74
IEEE Circuits and Systems Magazine - Q4 2020 - 75
IEEE Circuits and Systems Magazine - Q4 2020 - 76
IEEE Circuits and Systems Magazine - Q4 2020 - 77
IEEE Circuits and Systems Magazine - Q4 2020 - 78
IEEE Circuits and Systems Magazine - Q4 2020 - 79
IEEE Circuits and Systems Magazine - Q4 2020 - 80
IEEE Circuits and Systems Magazine - Q4 2020 - 81
IEEE Circuits and Systems Magazine - Q4 2020 - 82
IEEE Circuits and Systems Magazine - Q4 2020 - 83
IEEE Circuits and Systems Magazine - Q4 2020 - 84
IEEE Circuits and Systems Magazine - Q4 2020 - 85
IEEE Circuits and Systems Magazine - Q4 2020 - 86
IEEE Circuits and Systems Magazine - Q4 2020 - 87
IEEE Circuits and Systems Magazine - Q4 2020 - 88
IEEE Circuits and Systems Magazine - Q4 2020 - Cover3
IEEE Circuits and Systems Magazine - Q4 2020 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021Q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q1
https://www.nxtbookmedia.com