M530 2-in-1 Antenna<\/a><\/li>\n<\/ul>\n<\/div>\n<\/p>\n
Peak gain is the maximum value across the operating band. Realised gain accounts for impedance mismatch losses and is almost always lower. A supplier quoting only peak gain is giving you the best number available, not the truthful one.<\/p>\n
The practical gap matters. An antenna specified at “5 dBi peak” might deliver 2 dBi at the band edges \u2014 which is exactly where your device operates when the network is congested and hands you its fallback band.<\/p>\n
Ask for:<\/strong> gain plotted across frequency, or at minimum the value stated at your specific bands of interest.<\/p>\n2. VSWR \u2014 across the band, not at one frequency<\/h2>\n
VSWR \u2264 2.0 is a common headline figure. The catch is that VSWR varies with frequency, and a single achieves-band-centre measurement tells you very little.<\/p>\n
A well-designed wideband antenna holds VSWR under roughly 2.5 across the whole specified range. If the datasheet gives one number with no plot, assume it was measured where the antenna performs best.<\/p>\n
Ask for:<\/strong> a VSWR plot over the full operating band.<\/p>\n3. Radiation efficiency \u2014 the number most often missing<\/h2>\n
This is the single most diagnostic value on a datasheet, and the one most frequently absent. Efficiency tells you what proportion of accepted power actually radiates rather than heating the PCB or the radome.<\/p>\n
Two antennas can advertise the same gain while differing by several dB in efficiency, because gain describes directionality and efficiency describes honesty. A compact antenna with mediocre efficiency converts a meaningful share of transmit power into heat \u2014 which shortens battery life and reduces range simultaneously.<\/p>\n
Realistic figures depend heavily on size and ground plane, which is precisely why some suppliers prefer not to publish them. In our experience, if efficiency is missing from a datasheet, requesting it is the highest-value single question you can ask.<\/p>\n
Ask for:<\/strong> total radiated efficiency, stated with the ground plane dimensions used.<\/p>\n4. Band coverage versus the bands you actually need<\/h2>\n
“698\u20132700 MHz” sounds comprehensive. Check it against your radio module. If your device must support LTE Band 71 (617\u2013698 MHz), a quotation starting at 698 MHz does not cover you \u2014 and the shortfall shows up as poor indoor coverage rather than a clear failure, which makes it expensive to diagnose.<\/p>\n
The same trap appears with regional variants. A part designed for the Chinese market may omit bands used in North America or Europe, which becomes a problem only after you have shipped.<\/p>\n
Ask for:<\/strong> explicit confirmation that your specific band list is covered, not just a range. Send the band list \u2014 a competent supplier will answer concretely.<\/p>\n5. Port-to-port isolation (MIMO and combination antennas)<\/h2>\n
For any antenna with more than one port \u2014 2\u00d72 MIMO setups or 2-in-1 through 7-in-1 combination units \u2014 isolation between ports determines whether those ports genuinely operate independently.<\/p>\n
Below roughly 10 dB of isolation, MIMO gains degrade markedly: you paid for two antennas and received something closer to one and a half. This is mostly an internal design problem, solved by physical decoupling structures, which are invisible from outside the radome.<\/p>\n
Ask for:<\/strong> minimum isolation across the operating band, not a typical value at one frequency.<\/p>\n6. Axial ratio for GNSS only<\/h2>\n
GNSS antennas are the exception to most of these rules because the signals are circularly polarised. The figure that matters is axial ratio \u2014 how well the antenna preserves circular polarisation, typically expressed in dB at a stated elevation angle.<\/p>\n
A GNSS antenna with excellent gain and poor axial ratio will still deliver weak fix quality, because roughly half a linearly mismatched signal is simply rejected. This is also why increasing gain past a point stops helping: above the noise floor the receiver does not need more signal, it needs cleaner signal.<\/p>\n
Ask for:<\/strong> axial ratio at your operating elevation range, alongside LNA gain and noise figure.<\/p>\n7. What the quotation leaves out entirely<\/h2>\n
The numbers above are all electrical. In practice several commercial and mechanical details decide project outcomes more often than RF specifications do:<\/p>\n
\n- Radome material.<\/strong> UV-stabilised fibreglass lasts 10+ years outdoors. Polycarbonate yellows and embrittles after roughly 3\u20135 years of direct sun. ABS is not a permanent outdoor material.<\/li>\n
- Ingress protection.<\/strong> IP67 is the practical minimum for permanent outdoor mounting; IP68 for anything exposed to standing water.<\/li>\n
- Cable and connector.<\/strong> Loss in a long thin cable quietly cancels antenna gain. RG174 loses considerably more per metre than RG316 or LMR400.<\/li>\n
- MOQ and tooling.<\/strong> A low unit price can assume a volume you will never reach, or hide tooling you have not been told about.<\/li>\n
- Lead time to sample versus to production.<\/strong> These frequently differ by weeks, and the second one is the number your launch date depends on.<\/li>\n<\/ul>\n
A checklist you can forward to any supplier<\/h2>\n
Send this list with your next RFQ. Suppliers who can answer it are the ones worth comparing:<\/p>\n
\n- Gain plotted across frequency, with the ground plane dimensions stated<\/li>\n
- VSWR plot across the full operating band<\/li>\n
- Total radiated efficiency, not just peak gain<\/li>\n
- Confirmation covering your specific band list and target markets<\/li>\n
- Port-to-port isolation minimum, for multi-port designs<\/li>\n
- Axial ratio and LNA noise figure, for GNSS<\/li>\n
- Radome material, IP rating, cable type and length<\/li>\n
- MOQ, tooling cost, sample lead time, production lead time<\/li>\n<\/ul>\n
Two things tend to happen when you send it. Some quotations quietly improve their numbers, and a few suppliers answer completely and quickly. The second group is where the real comparison happens.<\/p>\n
How we handle these questions<\/h2>\n
We design, simulate, prototype and measure antennas in the same building, which makes answering requests like the above straightforward \u2014 the data comes from our own measurements rather than being requested from a third party and relayed.<\/p>\n
Every design is modelled in HFSS and verified in our anechoic chamber before release. We publish efficiency figures rather than only peak gain, and we state the ground plane we measured on, because without it the number means nothing.<\/p>\n
Minimum order is 100 pcs for catalogue parts, samples ship within five working days of approval, and datasheets and 3D drawings are available without an NDA. If some of these parameters are still undecided on your side, that is a reasonable starting point for a conversation \u2014 send us what you know, including the rough parts.<\/p>\n
Send your frequency band, mechanical envelope and target volume \u2192<\/a> An RF engineer responds within one working day.<\/p>","protected":false},"excerpt":{"rendered":"Two antenna quotes can list the same frequency range and the same gain dBi, yet behave completely differently in the field. Here are the seven numbers that reveal what a quotation is really telling you \u2014 and how to compare suppliers without flying blind.<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"0","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[160],"tags":[],"class_list":["post-1378","post","type-post","status-publish","format-standard","hentry","category-technical-guides"],"_links":{"self":[{"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/posts\/1378","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/comments?post=1378"}],"version-history":[{"count":2,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/posts\/1378\/revisions"}],"predecessor-version":[{"id":1581,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/posts\/1378\/revisions\/1581"}],"wp:attachment":[{"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/media?parent=1378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/categories?post=1378"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/topantenna.com\/de\/wp-json\/wp\/v2\/tags?post=1378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}