{"id":1299,"date":"2026-07-22T14:13:12","date_gmt":"2026-07-22T14:13:12","guid":{"rendered":"https:\/\/www.uflowin.com\/?p=1299"},"modified":"2026-07-22T14:16:07","modified_gmt":"2026-07-22T14:16:07","slug":"flush-lens-droplet-and-horn-antennas-what-is-the-difference","status":"publish","type":"post","link":"https:\/\/www.uflowin.com\/ar\/flush-lens-droplet-and-horn-antennas-what-is-the-difference\/","title":{"rendered":"\u0647\u0648\u0627\u064a\u0627\u062a \u0627\u0644\u0639\u062f\u0633\u0629 \u0627\u0644\u0645\u0633\u0637\u062d\u0629\u060c \u0648\u0627\u0644\u0642\u0637\u064a\u0631\u0629\u060c \u0648\u0627\u0644\u0642\u0631\u0646: \u0645\u0627 \u0627\u0644\u0641\u0631\u0642 \u0628\u064a\u0646\u0647\u0627\u061f"},"content":{"rendered":"

Non-contact radar level transmitters for liquids can be equipped with different antenna designs, and each behaves very differently in real applications. This article compares three common antenna types\u2014flush lens antennas, droplet (lens) antennas and horn antennas\u2014from a pure hardware perspective, without considering specific process media.<\/p>\n\n\n\n

Flush Lens Antenna<\/h2>\n\n\n\n

Mechanical Design<\/h3>\n\n\n\n

A flush lens antenna is mounted so that the entire flange face is completely flat. The microwave lens is embedded inside the flange, so no part of the antenna protrudes into the vessel or process pipe, and there is no cavity or recess on the process side.<\/p>\n\n\n\n

The lens itself is a thin, flat fluoroplastic microwave window forming a smooth planar surface towards the process.<\/p>\n\n\n\n

Beam Characteristics<\/h3>\n\n\n\n

Among the three antenna types, the flush lens has the widest beam angle and the most divergent microwave field. Its focusing capability is the weakest, but the near-field blind zone is almost zero, which means it has virtually no measurement dead zone close to the flange.<\/p>\n\n\n\n

Mechanical and Surface Features<\/h3>\n\n\n\n

Because there is no protruding structure, the flush antenna carries no collision or interference risk with internals or agitators. The surface is perfectly flat, without any curved contour to guide liquid flow, and there is no internal cavity where product could accumulate.<\/p>\n\n\n\n

Signal Attenuation Behavior<\/h3>\n\n\n\n

The microwave is emitted perpendicular to the flat lens surface. Foam, buildup or sticky product can easily form a continuous film that fully covers the lens area, and this direct coverage causes the strongest signal attenuation among the three designs.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Installation Requirements<\/h3>\n\n\n\n

Flush antennas can be mounted on the smallest flange sizes or short standpipes, and they have no minimum insertion depth requirement. The nozzle or standpipe length is essentially unrestricted as long as the beam has a clear path.<\/p>\n\n\n\n

Droplet (Lens) Antenna<\/h2>\n\n\n\n

Mechanical Design<\/h3>\n\n\n\n

The droplet antenna uses a solid, one-piece lens that protrudes into the vessel in a rounded \u201cwater-drop\u201d shape. The entire structure is solid with no hollow cavity inside, and the external surface is a continuously smooth curved profile.<\/p>\n\n\n\n

Beam Characteristics<\/h3>\n\n\n\n

Its beam angle is moderate to slightly narrow, offering better focusing than the flush lens but not as strong as the horn antenna. The near-field blind zone remains very small, so it can still measure close to the mounting point.<\/p>\n\n\n\n

Mechanical and Surface Features<\/h3>\n\n\n\n

The outward curved lens naturally creates a flow-guiding surface, which helps product and condensate to run off. The solid design has no hidden cavities for buildup, but the external protrusion means there is some collision or interference risk with mixers, pipes or internal structures.<\/p>\n\n\n\n

Signal Attenuation Behavior<\/h3>\n\n\n\n

Condensate or sticky media on the curved surface tend to slide down along the lens, making it difficult for deposits to fully cover the critical microwave emission zone. As a result, signal blocking and attenuation are significantly weaker than with a flush lens that can be completely covered.<\/p>\n\n\n\n

Installation Requirements<\/h3>\n\n\n\n

Droplet antennas typically use standard DN50\/DN80 process flanges and require a small amount of free insertion space into the vessel. They are suitable for many common tanks and nozzles as long as the curved lens can extend into the free space without hitting internals.<\/p>\n\n\n\n

Horn Antenna<\/h2>\n\n\n\n

Mechanical Design<\/h3>\n\n\n\n

A horn antenna consists of a tapered hollow metal waveguide plus a front-end microwave lens. The interior is an empty conical cavity, and the whole horn body protrudes significantly into the vessel; this cavity serves as a reflection and focusing channel for the microwave.<\/p>\n\n\n\n

Beam Characteristics<\/h3>\n\n\n\n

Among the three antenna types, the horn has the smallest beam angle and the strongest focusing capability. It delivers the highest directionality and the greatest energy concentration at long measuring distances, but its near-field blind zone is the largest of the three.<\/p>\n\n\n\n

Mechanical and Surface Features<\/h3>\n\n\n\n

The hollow conical interior creates a recessed space where liquids, condensate and vapors can easily stagnate. Because the horn protrudes the farthest into the vessel, its collision and interference risk with internal structures and agitators is also the highest.<\/p>\n\n\n\n

Signal Attenuation Behavior<\/h3>\n\n\n\n

The hollow cavity is very prone to collecting impurities and water, which can directly block the microwave path. This makes signal attenuation and instability much more likely compared with the two solid antenna designs.<\/p>\n\n\n\n

Installation Requirements<\/h3>\n\n\n\n

Horn antennas require large-diameter process flanges, typically starting from DN80 and above. They also need longer standpipes or nozzles to provide sufficient installation space, and often include optional purge connections for periodic cleaning of the horn cavity.<\/p>\n\n\n\n

Hardware-Only Comparison<\/h2>\n\n\n\n

Below is a concise hardware-only summary of the three antenna types without considering foam, dust or specific process media.<\/p>\n\n\n\n

    \n
  • Flush lens antenna: does not protrude into the vessel, has the widest and most divergent beam, almost no blind zone, but is very sensitive to surface films that cover the lens and block the signal.<\/li>\n\n\n\n
  • Droplet antenna: solid curved lens protruding into the tank, beam width is moderate, natural flow-guiding surface, deposits are less likely to fully cover the microwave core area.<\/li>\n\n\n\n
  • Horn antenna: hollow conical shape with the most focused beam and best long-range performance, but the largest blind zone and higher buildup risk inside the cavity; supports purging and is limited to larger flanges.<\/li>\n<\/ul>\n\n\n\n

    Conclusion<\/h2>\n\n\n\n

    Choosing between flush lens, droplet and horn antennas has a direct impact on radar level performance, installation flexibility and maintenance requirements. Flush lenses favor hygienic, collision-free installations with minimal dead zone, droplet antennas balance focusing and self-cleaning behavior, while horn antennas deliver maximum long-range signal concentration at the cost of larger blind zones and higher buildup risk.<\/p>","protected":false},"excerpt":{"rendered":"

    Non-contact radar level transmitters for liquids can be equipped with different antenna designs, and each behaves very differently in real applications. This article compares three common antenna types\u2014flush lens antennas, droplet (lens) antennas and horn antennas\u2014from a pure hardware perspective, without considering specific process media. Flush Lens Antenna Mechanical Design A flush lens antenna is […]<\/p>\n","protected":false},"author":1,"featured_media":1301,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[17],"tags":[],"class_list":["post-1299","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/posts\/1299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/comments?post=1299"}],"version-history":[{"count":2,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/posts\/1299\/revisions"}],"predecessor-version":[{"id":1302,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/posts\/1299\/revisions\/1302"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/media\/1301"}],"wp:attachment":[{"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/media?parent=1299"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/categories?post=1299"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.uflowin.com\/ar\/wp-json\/wp\/v2\/tags?post=1299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}